Second-story additions, ground-floor room extensions and attached garage conversions across the Bay Area — drafted to tie into your existing structure cleanly and to survive plan check the first time.
An addition is a different kind of drafting problem than new construction, because everything you draw has to agree with a building that's already standing. The permit set has to show the new work relative to real existing walls, real existing roof framing and a real existing foundation — not the version on a decades-old set of plans that may not match what's actually in the ground. That's the core reason we lean on a Matterport 3D scan of the existing structure before drafting an addition: it captures the as-built dimensions, wall locations and roof geometry directly, so the "existing conditions" sheet in your permit set is accurate instead of approximate, and the new construction actually lines up with the old.
Scope varies a lot by project. A single-story rear extension that keeps the existing roofline and doesn't touch the foundation footprint can sometimes move through a lighter permit review. A second-story addition, an addition that changes the building footprint, or one that adds a bedroom is a full plan-check submittal — structural calculations, energy compliance (Title 24 / CF1R), and a complete drawing set showing how the addition connects to the existing structure. We scope which category your project falls into during the initial site visit, before we draft anything, so you know what you're actually signing up for.
New upper floor over an existing footprint. We draft to your jurisdiction's daylight-plane, setback and height-limit rules, and coordinate new floor framing with the existing structure below it — not just the roofline you're adding onto.
Bumped-out kitchens, family rooms, primary suites and bedroom additions. New bedrooms need to show a compliant egress window or door on the plans, and we detail how the new roof ties into the existing one instead of leaving it to the framer to figure out on site.
New garage space attached to the existing house, including the fire-rated wall and door assembly between garage and living space. For a detached or standalone garage instead, see our Garage, Carport & Workshop page.
New footings, foundation dowels and shear connections where the addition meets the existing structure — drafted alongside our structural engineering partners so the connection is actually buildable, not just drawn.
We check the existing foundation, roof framing and setbacks against your city's zoning to confirm what size and shape of addition is actually allowed on your lot.
A 3D scan of the existing structure captures real as-built dimensions, so the new addition is drafted to tie into what's actually there.
Full set drafted in Revit — existing-and-proposed floor plans, elevations, roof plan, sections and structural tie-in details.
If the city returns corrections on the structural connection or setbacks, we revise and resubmit until the set is approved.
In most Bay Area jurisdictions, yes — daylight-plane, setback and maximum-height rules are common for second-story additions because they control how much shadow and bulk the new floor adds relative to neighboring lots. The specifics vary by city and even by zoning district within a city, so we check your property's exact requirements at the site visit rather than assuming a standard envelope will fit. If the addition you want doesn't fit within the standard rules, we'll tell you that upfront along with what the alternative looks like.
Because an addition physically attaches to what's already built — the new foundation ties into the existing one, the new roof meets the existing roofline, and the framing has to line up. If those existing dimensions are wrong on the plans, the error doesn't show up until framing, when it's expensive to fix. A Matterport scan captures the existing structure's actual dimensions directly instead of relying on hand measurements or an old plan set that may not match what was really built, so the addition is drafted against reality.
Yes — a new bedroom needs a compliant egress window or door sized for emergency exit, which we detail on the drawings, and it factors into occupancy and smoke/CO alarm requirements for the whole house, not just the new room. It's a normal part of an addition scope, but it's one of the items reviewers check closely, so we draft it as a first-class requirement rather than an afterthought.
Residential or commercial, drafting or Title 24 — send a few details and we'll follow up with next steps and a free quote.
(408) 676-8747
Sunny Drafting & Design