Lot size is the first thing that will drive the size of your custom home. One must be very careful when tapping those emotions that arise while previewing lots to purchase. Here are some fundamental factors to consider before you pull the trigger. Consulting with an architect or builder familiar with the development can provide an objective and experienced opinion.
Size of Lot Matters for your New Custom Home

Floor Area Ratio commonly referred to FAR: This is the calculation of the allowable square footage of the home relative to the size of the lot which acts as one of the elements for jurisdictions to control the size, scale and massing of structures. This is often mandated by city or county planning departments and also by the local home owners association if one exists. Investigating both channels is important as each may have their rules and can sometimes conflict.
Example Lot Analysis
So for example let say you find a 1/2 acre lot which is 21,780 square feet. A calculation is applied to determine the size of the home that can be placed on the lot. Many jurisdictions simply determine a percentage of the lot size to establish the allowable square footage. For this article we will establish 35% as the allowable square footage also known as FAR.
21,780 X 35% = 7623 sft allowed for a half acre lot known as the FAR.
Now at first glance this seems like an ample size home but this is not the whole story. In order to determine that this 7,623 square feet meets your needs consider this.
The FAR includes:
- The primary home structure
- Attached garages
- Detached garages, shops or other accessory buildings.
- Exterior patios enclosed by 2 or three walls.
- Tall ceilings over an established maximum may count as twice.
Sample Home Project

So lets break down a potential new custom home on a 1/2 acre lot. The needs for each homeowner will vary greatly lets assume our client desires a new home to eventually retire in the Nakoma Resort. Our client has a broad range of interests from Golf, Boating, Mountain Biking, Skiing, Arts and Crafts and Entertaining with the ability to invite friends and family. Homes ideal for mountain living to comfortably achieve common desires include two master suites, two living areas, dedicated large areas for family gatherings, storage areas and closets, mud rooms and oversize garages both in square footage and heights. Additionally detached shops, garages and guest houses can serve the needs of those desiring to live in the Sierra Nevada Range.
A custom home project could be comprised of:
- Main Home: 3,500 sft.
- Oversized 2 car garage: 500 sft.
- Tall ceiling areas in primary living area: 1000 sft.
- Detached guest house with carport: 1000 sft.
This project totals 5500 sft. well under the allowable 7623 sft.
So the size of the lot is the first step to insuring you achieve the home of your desires.
Unfortunately that’s not it! There are several other factors that will dictate the size and shape of the home. Design criteria such as Building Envelopes, Setbacks, Public Utility Easements, Height Limitations, Impervious Coverage, Site Characteristics (orientation, rock outcroppings, trees, soils, neighboring properties) and Design Review Guidelines commonly mandated by separate committees within an Home Owners Association also known as the HOA.
Nakoma Resort is a special development with lots sizes commonly over 1 acre.
Bill Reid is a California licensed general contractor designing and building homes from Silicon Valley to the Sierras. Learn more about Bill and how to build your custom home at the Nakoma Resort and surrounding areas of The Lost Sierra.