Design Criteria Index

Building Tip: Ask your designer to outline design criteria usedAll too often a set of construction plans are submitted without the basic information spelled out on the front page as to what the plan is for.

A title box showing the owner, what the plans represent and where the structure is intended to be located was not part of the first page.

The drawings may appear professionally prepared, may have some sort of seal from a design professional on them, but without sitting down to truly study the drawings it is impossible to know what the basic design criteria is and how that was derived.

Last week’s article in the Weekly Adirondack gave a brief explanation on the snow load design criteria for roof systems located around the state.

There is a huge difference from where the Town of Webb is located compared to New York City, or other areas around the state.

Snow load is only one of a number of basic design criteria that is imperative that the local Code Officer understand.

Every building, no matter what it is used for, larger than 144 square feet, must meet the minimum design criteria for the location in which it is built.

And for additions, alterations and renovations other design criteria notes may be required.

The architect or engineer for the project must know what the minimum design criteria is for the location that the structure will be built in.

Anyone can produce a generic plan showing the traditional framing techniques like 2 X 6 walls, 2 X 10 floor joists, a roof truss system, standard poured foundation and then simply put a note somewhere that everything must meet the local code requirements.

By law the local Code Officer cannot design the structure.

The Code Officer can help the designer with the minimum design criteria information, but the designer needs to have this basic information to start.

When a set of plans are submitted to the Code Office and a title block spelling out everything is right on the front sheet, plan review becomes much smoother.

Design criteria should include, but may not be limited to, what code was used for design, what year or edition of the code, wind zone, seismic zone, ground snow load zone and how that was calculated, climate zone for energy conservation, type of construction, use and occupancy classification, fire load or fire area, type of sprinkler system [if required] and weather exposure.

There is even a zone for termites.

When a Code Office receives a set of plans that has no title box, that is not signed by the design professional, has no indication as to how everything was designed, as to what code was used or what standards were intended, plan review just got a little more time consuming.

Although plans are reviewed, now the review must pull out all the information to verify that the minimum design criteria were met.

To verify roof ground snow load, you can usually go to the span tables and charts in the Building Code and see if the proposed roof plan meets the minimum requirements.

That works for any place in New York State except in ground snow load zones of 80 or more.

The chart stops at 70 maximum.

This is intended to force the Code Official to insist on an engineered roof system, showing any increase based on elevation.

This can also include any site specific loading needs based on historical information and experience.

Help yourself by insisting that your designer includes all the design criteria for your project, and is clearly shown on the front sheet.

This will definitely speed up the plan review process.

This is a good idea no matter where your project is, because none of this type of information is local zoning laws, it’s all about the New York State Uniform Fire Prevention and Building Code.