Home Developers Explain The Anatomy of a Custom House
Home developers know a custom house is far more technical than picking finishes. Here is the anatomy: the systems, assemblies, and decisions that go into a real custom build.
What home developers actually deliver
From the outside a custom home looks like architecture. From the inside it is hundreds of integrated systems: structural, mechanical, electrical, plumbing, envelope, finish, and smart home. Each is designed and installed by a different specialist and has to work in concert with the others. Understanding the anatomy helps owners ask the right questions and recognize quality when they see it.
Foundation and structure
Below grade: concrete footings sized for the soil conditions revealed by the geotechnical report, foundation walls (usually 8 or 10 inch poured concrete), waterproofing membrane, perimeter drainage, and a slab on grade or suspended slab depending on basement design. Above grade: typically wood frame in BC's Lower Mainland, with engineered floor joists, structural insulated headers, and shear walls designed for seismic loads.
Building envelope
The envelope is what separates conditioned interior from the outside. Continuous exterior insulation, vapour barriers, air barriers, and rain screens make up the modern wall assembly. High performance windows (typically triple pane in Greater Vancouver), well detailed flashing, and engineered roof systems complete the package. The envelope is the single biggest factor in long term energy performance.
Mechanical systems
Modern custom homes include a forced air or hydronic heating system, often paired with heat pumps, an HRV or ERV for fresh air ventilation, hot water (storage tank or on demand), radiant in floor heating in bathrooms and basements, and increasingly air conditioning. The mechanical room layout, equipment selection, and zoning strategy directly affect comfort and energy bills for decades.
Electrical and smart home
A typical custom home has 200 amp service, dedicated circuits for kitchen and laundry, low voltage wiring for AV and networking, structured cabling for hard wired internet to every key location, and increasingly EV charger infrastructure in the garage. Smart home systems integrate lighting, climate, security, audio, and shading on a single controller.
Plumbing
Pex tubing has largely replaced copper for water supply lines, with home runs from a central manifold for easy isolation. Drain, waste, and vent piping is ABS in residential. High end fixture selection (faucets, shower trim, toilets) is an interior design decision; the rough in is engineering and code.
Interior finishing
Drywall, paint, flooring, cabinetry, countertops, doors, trim, hardware, plumbing fixtures, electrical fixtures, and appliances. This is what owners see and touch every day, and it is where most of the personality of a custom home lives. Major Homes coordinates all of these selections with a finish schedule that keeps the project on track and on budget.