The purpose of this chapter is to:
A. Safeguard the heritage of the Borough of Gibbsboro
by preserving that part of the Borough which reflects elements of
its cultural, social, economic and architectural history;
B. Preserve the integrity of design of the eighteenth,
nineteenth and twentieth centuries buildings and streetscapes within
the Historic District or historic site(s) not located within the district
and preserve the historic and architecturally significant buildings;
C. Maintain and improve property values;
D. Preserve and promote the Historic District or historic
site(s) not located within the district as an essential element of
municipal character and identity, as an important factor in the economy
of the Borough and the property values therein;
F. Promote the use of the district for the education,
pleasure and welfare of the citizens of the Borough and its visitors;
and
G. Further assure that construction, alterations, repairs,
replacements and other such improvements within the Historic District
and historic site(s) not located within the district shall be compatible
with the Borough's heritage.
For the purposes of this chapter, the following
words shall have the meanings indicated. Unless the context clearly
denotes otherwise, the singular shall include the plural, and the
plural, the singular.
ADDITION
The construction of new improvements as part of an existing
improvement when such improvement changes or affects the exterior
of a structure.
ADMINISTRATIVE OFFICER
The Historic Preservation Commission Chairman or other officer
designated by the Borough Council to issue exemptions and waivers
and handle administrative functions in accordance with this chapter.
[Amended 7-28-1999 by Ord. No. 99-3]
ALTERATION
A change in the appearance of a building, structure or site which is not otherwise covered by the definition of "demolition" or any other change for which a permit is required under Chapter
400, Zoning. Alteration includes the reroofing, cleaning or painting of a building or structure. Alteration shall include the word "alter."
BUILDING
A structure, its site and appurtenances created to shelter
any form of human activity.
CERTIFICATE OF APPROPRIATENESS
The written approval issued by the Planning Board when so
required prior to any work or activity commencing on property set
forth as within the boundaries of the Historic District, or historic
site(s) not located within the district, as listed in the boundaries
attached hereto.
CONSTRUCTION
The erection of a new building, structure or object. The
word "construction" shall include the word "construct."
DEMOLITION
The razing or destruction, whether entirely or in significant
part, of a building, structure, site or object. Demolition includes
the removal of a building, structure or object from its site or the
removal or destruction of a facade or surface. Demolition shall include
the word "demolish."
DESIGN
Exterior features, including mass, height, appearance and
the texture, nature and composition of materials.
HISTORIC DISTRICT
One or more historic sites and intervening or surrounding
property significantly affecting or affected by the quality and character
of the historic site or sites.
HISTORIC SITE
Any real property, man-made structure, natural object or
configuration or any portion or groups of the foregoing which has
been formally designated in the Master Plan as being of historical,
archaeological, cultural, scenic or architectural significance.
IN-KIND
Any repair or replacement of an existing architectural feature
with the same type of material, same shape, same style and same function.
OBJECT
A material thing of functional, aesthetic, cultural, historical
or scientific value that may be, by nature or design, movable, yet
related to a specific setting or environment (as a monument or historic
road marker).
PRESERVATION
The act or process of applying measures to sustain the existing
form, integrity and material of a structure. It may include work to
prevent further deterioration, ongoing maintenance or other similar
actions.
REHABILITATION
The process of returning a property to a state of utility,
through repair or alteration, which makes possible an efficient contemporary
use while preserving those portions and features of the property which
are significant to its historic, architectural and cultural values.
RESTORATION
The act or process of accurately recovering the form and
details of a structure and its setting as it appeared at a particular
period of time by means of the removal of later work or by the replacement
of missing earlier work.
SECRETARY
The Municipal Clerk or other official designated by the Borough
Council empowered to accept applications and record the meetings and
actions of the Commission.
[Added 7-28-1999 by Ord. No. 99-3]
SITE
The location of a significant event, a prehistoric or historical
occupation or activity or a building or structure, whether standing,
ruined or vanished, where the location itself maintains historical,
cultural or archaeological value regardless of the value of any existing
structure.
STREETSCAPE
The visual character of the street, including its architecture,
fences, gates, storefronts, signs, lighting, paving and relationship
of buildings to the right-of-way of the street.
All uses permitted in the Historic District shall be those designated by Chapter
400, Zoning, of the Borough of Gibbsboro. Such uses shall not be altered by further designation as being within the Historic District.
The maximum building height, minimum lot size, maximum lot coverage, street frontage, side yard, rear yard and other area, height, size and distance regulations within the Historic District shall be as designated for each zone as set forth in Chapter
400, Zoning, and shall not be altered by virtue of inclusion in the Historic District.
[Amended 10-27-2010 by Ord. No. 2010-05]
A. In accordance with the Municipal Land Use Law N.J.S.A. 40:55D-25d,
the Borough of Gibbsboro, having a population of less than 2,500 people,
has elected to vest the statutory powers of a historic preservation
commission in the Planning Board. Accordingly, the membership of the
Planning Board must include at least one member having the following
qualifications:
(1) Class A: A person who is knowledgeable in building design and construction
or architectural history and who may reside outside the municipality.
(2) Class B: A person who is knowledgeable or with a demonstrated interest
in local history and who may reside outside the municipality.
B. The Planning
Board in exercising its statutory powers of the Historic Preservation
Commission shall have the following powers:
(1) Prepare
a survey of historic sites of the municipality pursuant to criteria
identified in the survey report.
(2) Make recommendations on the Historic Preservation Plan element of
the Master Plan and on the implications for preservation of historic
sites of any other Master Plan elements.
(3) Advise on the inclusion of historic sites in the recommended capital
improvement program.
(4) Advise on applications for development regarding historic district
standards
(5) Provide written reports on the application of Chapter
400, Zoning, or other land development ordinances of the Borough of Gibbsboro to provisions concerning historic preservation.
(6) Provide technical assistance upon request to property owners on how
to preserve, restore and rehabilitate structures and to advise property
owners upon their request as to the accuracy of historic restoration,
including materials, placement of windows or openings, architectural
details, environment and color.
(7) Carry out such other advisory, educational and informational functions
as will promote historic preservation in the borough.
[Amended 10-27-2010 by Ord. No. 2010-05; 9-8-2021 by Ord. No. 2021-12]
A. Application for certificate of appropriateness. A certificate of appropriateness (COA) issued by the Planning Board shall be required before a permit is issued or, in the event that no other type of permit is otherwise required, before work or activities can commence on or about the exterior architectural features of a structure in the Historic District or historic site(s) not located within the district, which are subject to public view from a public street, way or place, including but not limited to construction, alteration, addition, repairs, replacement, restoration, rehabilitation, demolition or development for a lot and block located in the Historic District or historic site(s) not located within the district, as defined in this chapter. COA shall not be required for the exempt work or activities set forth in Subsection
B(1) and
(2) below.
B. When a COA is not required; exceptions.
(1) No certificate of appropriateness is required for the following activities:
(a)
Maintenance, repair, and replacement of existing windows and
doors using substantially similar material; installation of storm
windows that are compatible with the architectural period or design
of the subject structure;
(b)
Maintenance, repair, and replacement of existing roof material,
involving no change in the design, scale, material or appearance of
the structure;
(c)
Maintenance, repair, and replacement of existing roof structures,
such as cupolas, dormers and chimneys, using substantially similar
materials, which will not alter the exterior architectural appearance
of the structure;
(d)
Maintenance, repair, and replacement of existing shingles, clapboards,
or other siding maintaining the architectural integrity of the structure;
(e)
Maintenance, repair, and replacement of existing shingles, clapboards
or other siding, using substantially similar materials as that being
repaired or maintained;
(f)
Exterior painting of existing structures;
(g)
Maintenance, repair, and replacement to existing signs shutters,
outdoor displays, fences, hedges, street furniture, awnings, off-street
driveway and parking materials and sidewalks using substantially similar
materials for those items noted above being repaired;
(h)
The addition of new plantings;
(i)
Installation of fences; and
(j)
Sidewalks, paving, patios, stairways and decks.
(2) A certificate of appropriateness shall not be needed for repairs
or replacement wherein the proposed activity constitutes an exact
replacement of that which existed prior to the need for the repairs
or replacement in question. To receive this exemption, the property
owner shall submit an application to the Planning Board Secretary
for such repairs with a photo of the existing condition or conditions
and estimate of cost. Applications will be forwarded to the Administrative
Officer to inspect the property and determine if an exemption is appropriate.
The Administrative Officer shall provide a written report to the Construction
Officer confirming whether or not a permit may be issued pursuant
to this exemption.
C. When the property owner or the Administrative Officer is uncertain whether a proposed activity meets the criteria of an exemption pursuant to Subsection
B above, the Administrative Officer shall refer the matter for administrative review to the Planning Board Chairperson acting as HPC Chairperson.
[Amended 10-27-2010 by Ord. No. 2010-05]
A. Policy intent. In reviewing any application for certificate of appropriateness,
the Planning Board shall make their determinations as to whether an
application should be approved, approved with conditions or denied
on the basis of the purposes of this section, the provisions of the
chapter and the following criteria of review adapted from the Secretary
of Interior's Standards for Rehabilitation and Guidelines for Rehabilitating
Historic Buildings and the following design criteria. The standards
and design criteria are requirements. The guidelines and description
of styles and check list provide general design and technical recommendations
and shall be made available to applicants, their architects, contractors
and subcontractors. The approach taken by the Borough of Gibbsboro
in establishing design criteria in the Historic District, or historic
site(s) not located within the district, is based on the fact that
portions of the district have an architectural cohesiveness of a period
of time and therefore new construction, additions and major alterations
in the Historic District should have an appropriateness of design
which should enhance the historic character of the district.
B. Performance standards. The following standards shall be used in evaluating
any application for a certificate of appropriateness:
(1) Every reasonable effort shall be made by the applicant to provide
compatible use for a property which requires the minimal alteration
of the building, structure or site and its environment or to use a
property for its originally intended purpose.
(2) The distinguishing original qualities or character of a building,
structure or site and its environment shall not be destroyed. The
removal or alteration of any historic material or distinctive architectural
features should be avoided when possible.
(3) All buildings, structures and sites shall be recognized as products
of their own time. Alterations that have no historical basis and which
seek to create an earlier appearance shall be discouraged.
(4) Changes which may have taken place in the course of time are evidence
of the history and development of a building, structure or site and
its environment. These changes may have acquired significance in their
own right, and this significance shall be recognized and respected.
However, if an earlier appearance of a building is of primary significance,
then restoration may be the preferred treatment. Removal of later
changes may be allowed in certain cases if such changes alter, obscure
or destroy the building's character-defining space, materials, features
or finishes of the building as it appeared during its primary period
of significance.
(5) Distinctive stylistic features or examples of skilled craftsmanship
which characterize a building, structure or site shall be treated
with sensitivity.
(6) Deteriorated architectural features shall be repaired rather than
replaced, wherever possible. In the event that replacement is necessary,
the new material should match the material being replaced in composition,
design, color, texture and other visual qualities. Repair or replacement
of missing architectural features should be based on accurate duplication
of features.
(7) The surface cleaning of structures shall be undertaken with the gentlest
means possible. Sandblasting and other cleaning methods that will
damage the historic building materials shall not be undertaken.
(8) Every reasonable effort shall be made to protect and preserve archaeological
resources affected by or adjacent to any project.
(9) Contemporary design for alterations and additions to existing properties
shall not be discouraged when such alterations and additions do not
destroy significant historical, architectural or cultural material
and such design is compatible with the size, scale, color, material
and land character of the property, neighbourhood or environment.
(10)
Whenever possible, new additions or alterations to structures
shall be done in such a manner that, if such additions or alterations
were removed in the future, the essential form, and integrity of the
structure would be unimpaired.
C. Design criteria. In assessing design of any proposed additions or
new construction, the following design criteria shall be considered,
in conjunction with the standard of review set forth above by the
Planning Board. These design criteria shall be used to analyze the
effect that the change applied for would have on the structure or
improvements within the Historic District, or historic site(s) not
located within the district, or immediate surrounding areas, as follows:
(1) Area and height regulations. Maximum building height, minimum lot size, maximum coverage, etc., shall be as required in Chapter
400, Zoning, for the respective zones, except the Zoning Board of Adjustment or Planning Board may grant a variance solely for the purpose of preserving historic characteristics.
(2) Proportion of facade. The relationship of the width of the building
to the height of the front elevation shall be visibly compatible with
the building and places to which it is visibly related.
(3) Position of openings. The relationship of the width of the windows
to the height of windows in a building shall be visibly compatible
with the buildings and places to which they are visibly related.
(4) Rhythm of solids. The relationship of solids to voids in such facades
of a building shall be visibly compatible with the buildings and places
to which they are visibly related.
(5) Rhythm of spacing. The relationship of the building to the open space
between it and adjoining buildings shall be visibly compatible with
the buildings and places to which it is visibly related.
(6) Rhythm of entrances. The relationship of entrances and porches to
the street shall be visibly compatible to the buildings and places
to which it is visibly related.
(7) Relationship of materials. The relationship of materials, texture
and color of the facade and roof of a building shall be visibly compatible
with the predominate materials used in buildings to which it is visibly
related.
(8) Roof. The roof shape and pitch of a building shall be visibly compatible
with the buildings to which it is visibly related.
(9) Continuity of walls. Walls and open fencing shall maintain visual
compatibility with the buildings and places to which it is visibly
related.
(10)
Scale of building. The size of a building, mass of a building
in relation to open spaces, the windows and door openings, porches
and balconies shall be visibly compatible to the buildings and places
to which it is visibly related.
(11)
Directional expression. A building shall be visibly compatible
with buildings and places to which it is visibly related in its directional
character, whether this be vertical character or horizontal character.
D. The following reference documents, as they may be amended or superseded,
shall be used as design standards for the design of rehabilitation,
renovation, alteration or construction work within the Historic District
and as review standards by the Historic Preservation Commission:
[Added 3-11-2015 by Ord.
No. 2015-01]
(1) The
Secretary of the Interior’s Standards for Rehabilitation and
Illustrated Guidelines on Sustainability for Rehabilitating Historic
Buildings, U.S. Department of the Interior, National Park Service,
Technical Preservation Services, 2011.
(2) Sample
Guidelines for Solar Systems in Historic Districts, National Alliance
of Preservation Commissions, 2011.
E. Design Standards for Townhouse Development.
[Added 10-11-2017 by Ord.
No. 2017-10]
(1) Site requirements.
(a)
For development within the R-TH Residential Zone, the Gibbsboro streetscape elements consisting of an eight-foot-wide dual use concrete sidewalk with brick border, period lighting, brick walls and piers, fencing, street trees and foundation landscaping shall be installed along the frontage of South United States Avenue (both sides), Clementon Road and Haddon Avenue in accordance with the subdivision standards of §
358-18Q. All streetscape elements shall conform to existing Borough standards.
(b)
The entrance to residential buildings shall be at least two
feet and no more than six feet higher than the elevation of the sidewalk,
or in the absence of a sidewalk, the edge of cartway.
(c)
Sidewalks and bikeways internal to the site shall conform to the Borough subdivision standards in §
358-18O.
(d)
Streetlights shall be required along all street frontages, whether public or private, alleyways and parking lots conforming to the Borough subdivision standard in §
358-18P or as approved by the Board of Jurisdiction.
(e)
No garage door shall face directly upon an existing street.
(f)
All utilities on the site shall be placed underground, including,
but not limited to, public water and sewer, stormwater management,
electricity, publicly supplied heating and cooling, telephone, television
and internet services, and similar utilities for residential development.
(2) Building relationships and forms.
(a)
Developers are required to incorporate good architectural design
with respect to scale, proportion, massing and balance of elements.
Buildings shall be human-scaled and designed to serve both the needs
of the buildings' intended users and to create a positive contribution
to the public realm and to the surrounding community. The level of
quality of materials and degree of detailing required in a building
may vary according to the location of a building, its visibility,
prominence in the community, and proximity to pedestrian activity.
(b)
Special consideration. Greater articulation and detail in the
architectural design shall be given to buildings on the corners of
two intersecting public rights-of-way; or one public and one private
right-of-way. Of secondary importance is the public view of buildings
that form the streetwall along Clementon Road, South United States
Avenue and Marlton Avenue.
(c)
Orientation. The front facades and primary pedestrian entrances
of buildings should generally be oriented to face the public or private
street that will have the highest pedestrian use.
(d)
Buildings shall be designed with a base, middle or field and
top. The base shall generally be at least at the level of the first
floor window sill for primary exterior walls (see Exterior walls below).
For three-story buildings, the base may be the entire first floor.
The base on primary exterior walls shall project a minimum of four
inches from the field. On secondary exterior walls (also see Exterior
walls below), the base shall consist of the foundation and a skirting
board at least six inches in width as a transition to the field of
the façade from the foundation. On three-story buildings where
the base does not extend to the second floor, a transition line shall
be introduced in between the first and second floors. The top shall
have a cornice consisting of eave, soffit, fascia and/or rake board
and shall continue around all sides of the building. The minimum projection
from the field shall be 12 inches in depth. The rhythm, patterns,
and ratio of solids (walls) and voids (windows and doors) of the buildings
should relate to historical proportions for the style of residence
being designed.
(e)
No more than two townhouses' primary exterior walls shall be
at the same vertical plane. The offset between townhouses shall be
a minimum of two feet.
(f)
Each townhouse shall incorporate a porch or masonry stoop attached
to the façade containing the front entrance door. The porch
shall have a minimum dimension of six feet in any direction measured
to the inside of the railing. A stoop shall have a minimum floor area
dimension of four feet in any direction.
(3) Exterior walls.
(a)
Primary exterior walls shall be constructed of standard brick
(Glen-Gery Sandford or approved equal). Primary exterior walls shall
include those facades facing upon an existing or proposed street,
whether public or private. Secondary exterior walls shall be any other
building facade. Secondary facades may consist of cement fiber board,
wood siding, insulated vinyl siding with no or faint woodgraining
at least 0.046 inch in thickness, or stucco, either three-part cementitious
stucco or synthetic stucco.
(b)
Cement fiber board, wood siding and vinyl siding shall have
a minimum exposure of four inches and a maximum exposure of eight
inches.
(c)
Building corners. The brick on primary exterior walls shall
be wrapped around any corner onto a secondary exterior wall a minimum
width of 16 inches. Any primary exterior wall exposed by an offset
shall be brick-faced at least up to the level of the soffit. Where
two secondary exterior walls meet at an outside corner, a corner board
with a minimum width of six inches on each façade shall be
used, unless the field material is stucco or synthetic stucco.
(d)
Brick coursing. Brick coursing shall be running bond for the
field. Window and door headers shall be soldier course or a keystone
arch/lintel. Window sills shall be bullnose or standard brick turned
sideways to create a rowlock with a minimum slope sufficient to shed
water away from the building. Decorative trim brick may be used for
the required transition line between the base and field, between the
first and second floors of a three-story building and to demarcate
the soffit.
(e)
Exterior walls shall consist of one or two field materials plus
a trim material, excluding the foundation.
(f)
The skirting board, corner boards and soffit on secondary exterior
walls are intended to create a frame within which the field material
of the secondary exterior wall is placed (not applicable to stucco
and synthetic stucco finishes).
(g)
Trim material shall have the appearance of smooth-planed wood.
(h)
Colors of the materials shall be limited to a single color for
each field material and two for trim material.
(i)
Poured concrete or concrete block foundations shall be permitted
on secondary exterior wall facades. Such foundation shall be exposed
no more than 12 inches above grade adjacent to hard surfaces and 18
inches for soil surfaces. Foundation that is exposed more than six
inches shall be painted to match the principal color of that wall.
(j)
Any chimney visible to the naked eye from the exterior of the
townhouse shall have a brick facade.
(4) Fenestration
(a)
Windows shall be six lites over six lites, double-hung, with
the following exceptions:
[1]
Clerestory windows may be one or two lites high and at least
three wide.
[2]
Transom windows shall be no higher than one lite and with at
least three lites in width.
[3]
Side lights shall be no wider than one lite and at least three
lites high.
[4]
Accent windows, such as fan windows, shall be exempt from these
requirements.
(b)
Windows shall be inset a minimum of four inches from an exterior
masonry wall and to the degree feasible from other wall materials.
(c)
Exaggerated woodgrain-look casing shall be avoided.
(5) Entranceways and porches.
(a)
Front door entrances shall be the most prominent element when
present in the primary exterior wall.
(b)
The entrance door shall be proportionately related to the heights
of the windows and the spacing between the door and window.
(c)
Front doors shall be a rail and stile design with inset panels.
If fenestration is desired, it shall be inserted between the rail
and stile. Crossbuck designs shall be avoided.
(d)
Other exterior doors shall match the rail and stile pattern
of the front door but are not required to match any lites within the
door.
(e)
Double front doors shall be avoided. Where added width is desired,
the preferred alternative is the use of side lites.
(f)
Railings and porch posts should be the same style as the porch
railings and posts if the two design elements occur on the same exterior
façade.
(g)
Railings and porch posts on the stoop should be the same style
as porch railing and posts if the two design elements occur on the
same exterior façade.
(h)
Porch posts shall be wider than the railings attached to them.
Porches shall have handrail and vertical balusters connected between
posts except where they would impede access. Handrail and balusters
shall be milled or formed for that purpose and proportional to the
size of the porch posts. Porch posts should be in line with the architrave
of the entranceway. Porch floors shall be wood or composite wood.
The width of the porch floor planking shall be no greater than six
inches.
(6) Roofs.
(a)
The style of roofs shall be gable.
(b)
Roof materials shall be slate, synthetic slate, or dimensional
asphalt shingle.
(c)
The roof pitch shall be no less than 6 to 12 (ratio of rise
to run).
(d)
All penetrations, including but not limited to plumbing vents,
exhaust vents, pipes, and flues, shall be located on the least visible
side to the extent feasible and painted to match the sloped roof,
excepting chimneys.
(7) Fences.
(a)
Fences shall be permitted between lots and in the side yards
or secondary front yards of corner lots facing on a private street,
alley or parking lot.
(b)
Fences between lots shall be a minimum height of four feet and
a maximum height of six feet. For any fence in excess of four feet
in height, the top one foot shall be pickets, lattice work or similar
semi-open fencing and the lower portion shall be solid. Any fence
facing a public or private street shall be no greater than four feet
in height and shall be at least 25% open.
(c)
No fence shall be located in a clear sight distance triangle.
(d)
Fence materials shall be as approved by the Board of Jurisdiction
during the application review process.
(e)
Gates in fences shall be constructed of the same material as
the fence.
(8) HVAC equipment.
(a)
No HVAC equipment shall be inserted through an exterior wall
or window, excepting intake and exhaust ventilation, and connections
between exterior air compressors and heat pumps or similar equipment
to interior equipment.
(b)
No HVAC equipment shall be roof mounted, except for on a garage
roof.
(c)
All HVAC equipment shall be screened from public view by fencing,
landscaping or building.
[Amended 10-27-2010 by Ord. No. 2010-05]
A. Every building and site in the Historic District, or historic site(s)
not located within the district, listed on the State or National Register
of Historic Places and described in the Inventory and Description
of Houses, Buildings and Sites in Gibbsboro as a contributing building
and site to the district shall not be demolished or moved without
the Planning Board considering its demolition or moving in relation
to its impact on the streetscape and neighbourhood regardless of whether
or not it is of historic architectural significance.
B. On any application for a certificate of appropriateness to demolish
any structure in the Historic District, or historic site(s) not located
within the district, the Planning Board shall hold a public hearing.
At this public hearing, the Planning Board shall hear from any interested
party or organization as to whether the permit shall be issued. In
making its determination, the Planning Board shall use the criteria
set forth in this chapter. If the Planning Board determines that demolition
is not appropriate, it may postpone issuance of the permit for a period
of time, not to exceed 12 months, and the Planning Board may hold
other hearings to determine if there is some other means to preserving
the building. The Planning Board is empowered to work collaboratively
with the applicant on feasible plans for preservation of structures
where moving or demolition thereof would be a great loss to the public,
the Borough, the streetscape and the neighborhood. In the event that
it is shown that the owner has a reasonable economic use of the property
and that the structure should be preserved on the basis of the standards
set forth in this chapter, the Planning Board may deny the application
for a certificate of appropriateness to demolish the structure.
C. When it is necessary to move an historic building to another site
within the borough to preserve it, upon approval of the relocation
plans by the Planning Board, said building may be relocated, provided
that it fulfills the area regulations of said zone as to lot size,
setback and yard area unless appropriate variances are obtained.
All work performed pursuant to the issuance
of a certificate of appropriateness for the alteration or demolition
of a building, structure, site or object subject to the review of
the Historic Preservation Commission and the Planning Board shall
conform to the requirements of the permit. It shall be the duty of
the administrative officer to inspect from time to time any work performed
pursuant to such permit in order to ensure compliance. In the event
that work is not being performed in accordance with the permit requirements,
the administrative officer shall issue a stop-work order, and all
work shall cease until the work is brought into conformity with the
requirements of the permit. The work to be performed under a certificate
of appropriateness shall commence within one year of its issuance,
or the certificate shall be deemed null and void.