Before you design the house, find out what the property can support.

How many square feet can you build?

Start with the exact jurisdiction and parcel. A Los Angeles mailing address may be inside the City of Los Angeles or another city with different rules. For City of Los Angeles property, ZIMAS shows the base zone, height district, planning cases and many overlays.

The answer may be limited by several rules at once:

• FAR or Residential Floor Area: how much counted floor area is allowed relative to lot area.
• Lot coverage: how much of the lot may be covered by the building footprint.
• Setbacks: required open areas at the front, sides and rear.
• Height and stories: controlled by zone, height district, roof form, slope and overlays.
• Overlays: hillside, coastal, historic, specific-plan, design-review, fire and other controls can be more restrictive.
• Site constraints: grading, access, trees, utilities, drainage, easements and geotechnical conditions can reduce the practical envelope.

How do you check maximum height?

Height is not just a number from the sidewalk. The code may define where measurement begins, how grade is established, how roof form is treated and whether sloped portions of the lot change the calculation. Ask the architect to place the allowed height plane on a survey or topographic plan and identify every assumption.

What is the new-construction process?

1. 01

   Property and feasibility

   Survey, title/easements, zoning and overlay review, utilities, preliminary budget and financing conversation.

2. 02

   Architectural concept

   The architect develops the program, floor plans, massing, site plan and early exterior direction.

3. 03

   Interior design coordination

   Kitchen, bathrooms, cabinetry, finish direction, reflected ceiling and lighting decisions feed back into the architectural set.

4. 04

   Consultant engineering

   Structural, civil/grading, geotechnical, mechanical, electrical, plumbing and other consultants are added as the project requires.

5. 05

   Energy and code documentation

   California energy documentation, window/door performance, equipment and envelope specifications are coordinated—not selected at the last minute.

6. 06

   Plan check and corrections

   The reviewing agencies issue comments. The design team coordinates responses and revised sheets until permits can be issued.

7. 07

   Pricing and selections

   The contractor prices a coordinated set, identifies allowances and long-lead items, and builds a schedule.

8. 08

   Construction and inspections

   Site work, structure, rough trades, envelope, finishes, commissioning, final inspections and closeout.

The sequence overlaps. Structural and energy decisions should begin before the design is “finished,” because large glass openings, cantilevers, roof forms and mechanical systems affect both architecture and cost.

How much does it cost to build?

For complete residential new construction above 1,000 square feet, DG Builders uses these simple early-planning baselines:

A complete project budget may also need separate allowances for land, architecture and interior design, engineering and surveys, permits and agency fees, demolition or abatement, utilities, unusual grading or hillside work, shoring, retaining walls, basements, pools, landscape, owner-purchased items, financing and interest, escalation and contingency. Premium glazing, millwork, appliances and building systems can materially increase the construction number.

Why can’t an addition be priced only by its new square footage?

An addition changes an existing house. The contractor may need to open and protect existing areas, connect new structure and foundations, transfer loads, extend or upgrade electrical, plumbing and HVAC systems, integrate roofs and exterior walls, and blend floors, paint and finishes. Repairs, occupied-home logistics and hidden conditions can add work outside the new footprint.

That is why an addition should be priced from its complete scope. The new square footage is useful information, but multiplying it by one rate can miss a large part of the real job.

How do owners finance new construction?

• Construction-only loan: short-term funding released through lender-controlled draws; usually refinanced or paid off at completion.
• Construction-to-permanent loan: construction financing intended to convert into a long-term mortgage after completion.
• Land equity: owned land may contribute to the borrower’s equity position, but the lender decides how it values the land and project.
• Cash plus construction loan: owners fund design, permits or early costs, then use loan draws during construction.
• HELOC or home-equity loan: more common for additions when another property or existing home has sufficient lendable equity.

Lenders commonly review credit, income/liquidity, land ownership, appraisal based on plans, plans and permits, construction contract, budget, contingency, schedule and contractor qualifications. Compare draw procedures, inspection fees, interest reserve, rate locks, conversion terms and what happens if cost or schedule changes.

Important construction choices

Windows and exterior doors

Select performance and opening type before brand: fixed, casement, awning, slider, folding or multi-slide; then evaluate frame material, sightlines, energy values, water testing, coastal exposure, lead time, service and budget. Exact model numbers must match the energy documents and rough openings.

A “flush track” multi-slide door minimizes the visible threshold, but it still needs a manufacturer-approved sill condition, waterproofing transition and drainage strategy. Water must be collected and directed away; simply burying a standard track in tile is not a safe detail.

Waterproofing and hot mop

Waterproofing is the complete water-management system behind tile. Hot mop is one traditional shower-pan method used at the floor; it does not replace waterproofing at walls, benches, niches, curbs, penetrations or transitions. Other listed systems use sheet or liquid-applied membranes. The drain, slope, membrane and flood test must work as one approved assembly.

Roof choices

Changing from shingles to tile can add substantial dead load. Do not assume the framing can carry it; the existing structure and new assembly should be evaluated and permitted as required.

Which walls can be removed?

A wall can carry roof, floor, ceiling or lateral loads even when it does not look important. Plans, framing direction, foundations and field investigation help identify the load path. Do not rely on tapping the wall or on a visual guess. A structural engineer should evaluate walls when the load path is uncertain or an opening changes structural or seismic behavior.

Insulation and sound control

Choose assemblies, not only products. Thermal design considers roof/wall/floor location, required energy performance, moisture and air sealing. Sound control may combine insulation in the cavity with resilient channels or clips, multiple drywall layers, sealant, solid-core doors and separation of plumbing/mechanical vibration. “Soundproof” is rarely one material.

How should exterior and interior colors connect?

Build a fixed palette in this order: materials that cannot easily change, major wood and stone, cabinet/door finishes, wall paint, metals, then fabrics and accessories. Compare every sample in the actual orientation and light. Repeat a limited number of undertones across connected rooms instead of matching every color exactly.

Landscape, hardscape and drainage

Landscape design begins with sun, soil, irrigation, mature plant size and water use. Hardscape includes patios, walks, walls, steps, driveways, gravel and other non-plant surfaces.

Pavers or poured concrete?

Pavers provide joints and can allow easier localized repair; some systems are permeable when designed with the correct base. Concrete can create larger continuous surfaces but can crack and requires properly planned joints, base preparation and drainage. Neither material fixes a poor slope or an undersized drain system.

Where should rainwater go?

Drainage should move water away from the building without sending a problem onto a neighbor or public area. The design may use surface slope, area drains, channel drains, roof drains, overflow paths, infiltration or approved discharge points. Soil and hillside conditions can require civil or geotechnical input.

How high can a front fence or gate be?

Do not use one number for every property. Height can depend on where the fence sits relative to required yards, driveway visibility, retaining walls, slope, corner-lot visibility, overlays and permits. Moving a fence deeper into the lot may place it in a different required-yard condition, but that must be verified on a site plan—not treated as a loophole.