Home Additions
Add square footage that looks like it was always meant to be there.
Materials
What we install vs. what corner-cutters use.
Foundation
Poured concrete footing to code frost depth, dowelled to existing
Sonotubes or a slab poured on grade
Why it matters: Frost heave will crack a slab-only addition within 3 winters.
Framing
Engineered ridge, LVL headers, hurricane ties, sheathing seams taped
Undersized headers, no ties, unsealed sheathing
Why it matters: Structural engineering keeps roofs on and prevents drywall cracks.
Siding
Match existing profile, exposure, and color; new WRB behind
Nearest-match vinyl and caulk the transition
Why it matters: A proper tie-in disappears; a bad one advertises 'addition' from the curb.
Roofing
Continuous shingle courses where possible, ice-and-water at valleys and eaves
Butted-up new roof against old with a bead of tar
Why it matters: Correct valley + ice-shield details are what stop the leak 5 years later.
HVAC
Manual-J load calc; new ducting or a dedicated mini-split
Poking a vent into the closest existing duct
Why it matters: Sizing the system is why the new room isn't 15° off the rest of the house.
Process
A predictable path — with real durations.
Design & engineering
6–10 weeksArchitectural, structural, permit set.
Permits
3–8 weeksJurisdiction-dependent; we manage the whole submittal.
Site & foundation
2–3 weeksExcavation, footings, foundation, waterproofing.
Framing & dry-in
3–5 weeksFraming, roof, windows, weather barrier.
MEP rough-in
2–3 weeksPlumbing, electrical, HVAC, inspections.
Finish
6–10 weeksInsulation, drywall, floors, trim, paint, fixtures.
Why us
Why homeowners pick Modern Builders for home additions.
An addition has to look like it was always there — matched roof lines, matched siding profile, tied-in foundation, and structural connections engineered by a licensed engineer. We don't bolt boxes onto houses.
FAQs
Answers before you ask.
Do we need an architect?+
For anything over ~200 sq ft or with structural changes, yes. We work with a short list we trust or with your architect.
Can you match old brick or stone?+
Often yes — we source reclaimed or custom-blended units. It's worth the extra week.
How disruptive is it?+
We keep the existing house sealed until the last moment; most clients only feel the disruption in the final tie-in week.
Related reading
Go deeper before you decide.
Get a quote — we do it right.
Fixed-price proposals, real timelines, no corners cut. Tell us about your home additions project.
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