ActiveYards Home Additions & ADU Nationwide

ActiveYards Home Additions & ADU: The Redwood City Owner’s Guide

ActiveYards home additions and ADU components in Redwood City typically run $45,000-$130,000 installed, depending on whether we’re matching an existing footprint or building a detached unit from slab to roof. We stock ActiveYards-compatible structural hardware, window systems, and exterior cladding on our Redwood City trucks, and most replacements can be spec’d and started within a week of your call. Most owners first notice a problem when the addition’s thermal envelope fails - a window that won’t seat, siding that gaps, or a door frame that’s pulled away from the rough opening after a wet Redwood City winter.

Call (650) 560-7228

Which ActiveYards Models This Applies To

ActiveYards builds under several product lines, and the hardware differs materially between them. The Serenity series uses a proprietary aluminum window frame with a built-in thermal break; the Chesterfield and Glencoe lines share a steel-reinforced vinyl jamb system. Check the etched code on the window spacer or the stamped label inside the door hinge mortise - it’ll read “AY-” followed by a four-digit series code. The 2200 and 2400 series are cross-compatible for jamb extensions; the 2600 series uses a deeper profile that won’t retrofit without reframing.

We source OEM ActiveYards hardware through their West Coast distribution in San Jose, but we also stock quality equivalents from Andersen and Milgard for discontinued lines. The OEM route preserves your warranty and matches the original finish exactly; aftermarket saves roughly 15% and performs to the same spec, though the anodized color may read slightly different in direct sun. For Redwood City’s coastal-influenced climate - salt air, high humidity, temperature swings between the fog line and the inland ridges - we generally recommend the thermal-break OEM on anything facing west or within two miles of the Bay.

Signs Your ActiveYards Home Addition or ADU Is Failing

• Window sash won’t lock or lift. The balance mechanism, a coiled spring or block-and-tackle system inside the jamb, has fatigued. In Redwood City, we see this most often on south-facing units where daily expansion cycles wear the polymer guides faster than the manufacturer rates them.
• Visible gap between the door frame and the rough opening. The shims have compressed or the fasteners have backed out, usually because the original crew used non-galvanized nails in pressure-treated lumber. The frame is no longer square, and the weatherstripping can’t compensate.
• Siding panels bow or rattle in wind. The fastening pattern was too sparse for the exposure, or the expansion clips have broken. ActiveYards’ horizontal siding needs a clip every 16 inches in wind zones; Redwood City’s gust corridors, especially up toward Emerald Hills, exceed the base spec.
• Water staining at the ceiling joint where addition meets existing house. The step flashing was either omitted or installed without adequate overlap. This is a common failure in ActiveYards additions where the original contractor relied on caulk instead of proper metalwork at the valley.
• Floors feel spongy or slope toward the exterior wall. The sill plate has rotted, or the post-and-beam foundation has settled. Redwood City’s clay-heavy soils in the Stambaugh-Heller area hold moisture against the rim joist; we’ve replaced three in the past two years where the drainage plane failed.

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Replacement Cost & What’s Included

For a full ActiveYards addition or ADU replacement in Redwood City, expect $45,000-$130,000 depending on square footage, foundation type, and whether we’re tying into existing utilities. A partial rebuild - say, re-siding and re-windowing a 400-square-foot unit while preserving the slab and roof - typically falls in the $45,000-$75,000 range. New detached ADU construction from dirt to certificate of occupancy runs $90,000-$220,000.

Our written quote itemizes every line: demolition, rough carpentry, structural hardware, windows and doors, insulation, MEP rough-in, finish materials, and permits. Under Clause 1 of the Haven Standard, that price is fixed before we start. No change proceeds without a signed change order, which is why our projects finish within a few percent of the original number. Every job carries our 365-Day Done Right Promise and a documented photo record of each phase.

DIY or Call Us?

There’s a safe middle ground here, and then there’s the line where it gets expensive fast.

An owner can check the window label, photograph the gap pattern, and verify whether the door still locks square - all useful diagnostics that save us time on the site walk. What we don’t recommend is removing a window unit, cutting into the WRB (water-resistive barrier, the housewrap or felt behind your siding), or attempting to re-shim a door frame that’s supporting structural load. Redwood City’s permit office requires a signed-off inspection for any structural modification to an ADU, and the fines for unpermitted electrical or plumbing rough-in start at double the permit fee.

We carry ActiveYards-compatible jambs, sashes, and flashing kits on our Redwood City trucks. Call (650) 560-7228 and we’ll schedule a free estimate with a written price before any work starts.

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