How Do You Compare Custom Home Design Options?

Custom home designs are generally more difficult to compare than finished homes on the market because no one has ever built the home that is being considered. As a result, two designs that appear to have similar square footage and finishes can have very different costs, risk to schedule and to resale value. It is the job of the homeowner to uncover these differences before the designer starts creating a set of plans that are difficult and/or expensive to change.

Normalize the budget before you compare anything else

The scope of design options can only be compared if written out in full for the same scope of work. One builder’s ‘shell and finish’ plus allowances may be entirely different from another builder’s ‘complete package’ which includes site work, septic, and landscaping. Even a builder who offers the same ‘finished’ product may draw a line at the foundation for items such as the driveway, permits and impact fees, etc.

Create a scope sheet and have each builder complete it on a line by line basis. The scope sheet should outline who is responsible for site work, utility hook-ups, driveway, permits/impact fees, appliances, window treatments, etc. Through final grading.

Examine the allowance structure

The source of failure in budgets, especially for features such as plumbing and HVAC, is the use of allowances for builder grade products for trim, and those fixture allowances will not carry the client’s chosen selections. Require the builder to list out all the products that will be purchased for each allowance instead of just a number, and compare that to your design intent. If an allowance does not allow for the selections you have chosen for your home then reduce the number for that allowance during comparisons with other builders instead of discovering the shortfall at selections time.

Read floor plans for cost drivers, not just flow

Instead of focusing on areas of a home’s plan, most people focus on things such as circulation, sight lines between living areas, and the way the rooms of the home are situated in relation to each other. While these are important aspects to a plan, the cost of a plan is based on the geometry or shape of the home and most people do not even notice the differences in the way that a similar program can vary in cost by as much as 15% based on the way that the footprint and the roof are organized.

• Perimeter to area ratio. Every jog in the exterior wall adds foundation, framing, flashing, and labor without adding usable space.
• Roof complexity. Multiple intersecting planes, dormers, and varied pitches multiply framing hours and create more opportunities for water intrusion.
• Plumbing core distribution. Stacked and clustered wet walls cut rough-in cost sharply compared with fixtures scattered across the plan.
• Span lengths. Great rooms with long clear spans require engineered beams and sometimes steel, which affects both cost and lead time.
• Ceiling variation. Coffered, vaulted, and tray treatments are drywall and trim labor, priced per room rather than per house.

Compare plans at the same level of development

Do note, however, that the cost to develop a concept (schematic design) will always be less than the cost to develop a developed design (design development). A skilled architect and/or builder will be able to indicate to you what design decisions have not yet been made and you can take that into consideration when comparing “apples to apples”. It is worth sitting down with experienced Winston-Salem custom home builders, who can walk you through the many assumptions buried in a very early sketch.

Score design choices against budget, schedule, and durability

Not all design options will have the same ‘long’ term effects on your budget. Some upgrades will only cost money once and then be ‘walled’ up and never thought about again. Other design options will cost money and extend the construction period of your home and possibly create future maintenance issues.

Design choice	Cost impact	Schedule impact	Long-term consideration
Upgraded insulation and air sealing	Moderate, one time	Minimal	Lower operating cost, hard to retrofit later
Custom cabinetry over semi-custom	High	Adds four to ten weeks lead time	Durable, highly visible daily
Expanded window and glass area	High	Long lead on specialty units	Thermal performance and seal maintenance
Complex exterior material mixes	Moderate to high	More trades sequenced	More transitions to maintain and seal
Rough-ins for future finishes	Low	Negligible	Preserves options without current spend

Separate reversible from irreversible decisions

Things that get encased in the walls of your home (e.g. Cabinets, etc.), things that are below grade, things that are structural in nature, these items must be in your initial budget. Items like paint, flooring, countertops, etc. Can be changed later with little cost or disruption. Additionally, items like framing for future installation of items like an elevator, running of extra conduit for future installation of things like speakers, etc. And oversized panels for future installation of items like solar panels, etc. Cost very little to include now and can be very expensive to retrofit at a later date.

Test the timeline against its assumptions

The schedule for delivery of a home is a statement of a builder’s assumptions about issues outside of their control. Compare proposals based on the assumptions in the schedule rather than the date shown for completion.

1. Permitting duration based on recent local approvals, not an average.
2. Lead times for windows, cabinetry, HVAC equipment, and specialty trim, with order-by dates identified.
3. Weather contingency for excavation and exterior work in the relevant season.
4. Selection deadlines, and what happens to the schedule when one slips.
5. Inspection sequencing and any known bottlenecks in the jurisdiction.

And a builder’s guess for how long it will take to complete your home (the “project schedule”) is a claim about things outside of his or her control (e.g. Weather, other contractors). The longest timeline in your proposals is likely the most accurate. Ask each builder to list out the 3 things that they believe will delay your project and how they would deal with each.