Additions
Home additions in Louisville, KY
More room without leaving the neighborhood you love: primary suites, family rooms and second stories that look like they were always there.
- ★ 5.017 Google reviews
- Design-buildOne firm, one contract
- East EndTen communities
- Major projectsKitchens to whole homes
Design-build additions
Add space, keep the house
Many East End families love their street, their schools and their trees, and simply need more room. An addition gives you that without the cost and upheaval of moving. Done well, it fixes the floor plan of the whole house, not just the new rooms.
Additions are where design-build matters most. They involve zoning setbacks, foundations, structure, rooflines, matching brick or siding, and tying new heating, cooling and electrical into the old. Keystone handles all of it, from the survey and zoning review through the final walkthrough, with one team accountable for both the design and the cost.
What we build
Additions that fit the house and the lot
Every addition starts with what the lot allows and what the existing house needs.
Primary suite additions
A bedroom, bath and walk-in closet on the main floor, often the key to staying in a home for the long term.
Family room additions
Open family rooms off the kitchen with vaulted ceilings, fireplaces and walls of windows to the yard.
Second-story additions
Building up on smaller lots, with structure reinforced below, and stairs planned so the old floor plan still works.
Dormers & attic conversions
Turning a 1½-story attic into bedrooms and a bath with shed or gable dormers.
In-law & guest suites
Self-contained suites with a bath and kitchenette for parents or adult children, including accessory dwelling units where zoning allows.
Kitchen bump-outs
Modest additions that give a kitchen room for an island, pantry or breakfast area.
Sunrooms & four-season rooms
Insulated, heated and cooled rooms with lots of glass, built as a true part of the house.
Mudrooms & entries
Drop zones, lockers and laundry between the garage and kitchen.
Signature looks
Three additions we love to build
The garden room
A single-story family room or sunroom that opens the back of the house to the yard, with tall windows and a vaulted ceiling.
The primary suite
A first-floor bedroom, bath and closet so you can stay in the house for decades. One of our most-requested additions.
The second story
Going up instead of out on a tight lot, with a new stair, structure checked by an engineer, and a roofline that matches the house.
Inspiration
Additions that belong
Photography shown is representative of the finish level we build. Keystone project photos are being added.
Louisville homes
What each East End lot allows
The right addition depends on the lot, the zoning and the house. These are the patterns we see most.
Narrow, older lots
In Crescent Hill and St. Matthews, lots are narrow and side setbacks tight, so additions usually go to the rear or up. Dormers and second stories on Cape Cods and bungalows are common.
Postwar ranches on modest lots
In Lyndon and Jeffersontown, rear primary suites and family rooms work well on ranches, often paired with opening the kitchen. Jeffersontown reviews zoning in-house under its own code.
Large and wooded lots
In Anchorage, Indian Hills and Hunting Creek, there's room to spread out, but tree protection, historic review in Anchorage, steep or rocky ground and HOA architectural review shape the design.
Design decisions
How we make an addition look original
- Rooflines first. We design the roof to extend the existing pitch and eave lines rather than bolting a box onto the back.
- Matching materials. Brick sourced to match, siding profiles and trim details carried through, and windows that match the existing style and proportion.
- Floor heights. We align new floors with old wherever possible to avoid steps between rooms.
- Heating and cooling. We check whether the existing system can serve the new space or whether it needs its own zone or system.
- Foundations. Footings at least 24 inches below grade for Jefferson County frost depth, with crawlspace or basement options.
- Circulation. We plan how you'll move through the whole house so the addition improves the existing plan instead of complicating it.
Planning your budget
What shapes the investment
- Foundation and site. Slopes, poor soil, trees and utilities in the way all affect excavation and foundation design.
- Up or out. A second story needs the existing structure checked and often reinforced. Building out needs lot space within setback rules.
- Tying in. Matching the roofline, siding, brick and interior trim takes skill and time, and it is what makes an addition look original.
- Mechanical systems. Your existing HVAC and electrical service may need to be upgraded to carry the new space.
- Approvals. Zoning setbacks, variances or local city review can add design time before a permit is issued.
We don't publish prices because every house is different. You get a fixed price at the end of design, before construction starts. Read the cost guide
Typical timeline
How long an addition takes
Typical ranges for our projects in the East End. Your actual schedule is set in your contract once the design is final.
- 8–16 weeks
Design & approvals
Survey, drawings, engineering, zoning review, fixed price.
- 4–8 weeks
Permits & ordering
Building permit, windows, trusses, long-lead items.
- 4–6 months
Construction
Foundation, framing, dry-in, rough-ins, inspections, finishes.
- 2–3 weeks
Finish & walkthrough
Final inspections, punch list, closeout.
Permits & approvals
Zoning, permits and review boards
Additions need a building permit and must meet the setbacks, height and lot-coverage rules for your zoning district and form district. Several cities in our area add their own review: Anchorage has its own zoning, a Historic Preservation Commission and a tree preservation plan requirement; Hurstbourne requires a city permit with drawings on a survey; Jeffersontown and Prospect review plans in-house; Middletown's historic district needs a Certificate of Appropriateness; and Lake Forest and Hunting Creek have HOA architectural approval. We map out every approval before design is finished.
The Keystone process
Six phases, no surprises
Each phase closes with your approval before the next begins, so the schedule, budget and selections are settled before construction starts.
Consultation
A walk through your home to understand how you live, what isn't working and what you want to change.
Design
Measured drawings and renderings, refined with you until the plan, the budget and the details agree.
Selections
Cabinetry, stone, tile, plumbing fixtures and lighting chosen with our designer, before anything is ordered.
Pre-construction
Permits, approvals, ordering and a firm schedule, all settled before the first wall comes down.
Construction
A dedicated project manager, protected floors and a clean, orderly site at the end of every day.
Walkthrough
A final review together, every punch-list item closed, and a home that's ready to live in.
Where we work
Across Louisville's East End
An addition in Anchorage's historic district is a very different project from one in Jeffersontown. Here's what we see in each place.
Louisville, KY 40207St. MatthewsDormers, second stories and rear family rooms on smaller lots
Louisville, KY 40206Crescent HillRear additions and attic suites on narrow grid lots
Louisville, KY 40207Indian HillsSuite and garage additions on wooded, hilly lots
Louisville, KY 40222LyndonRear primary suites on 1950s ranches
Louisville, KY 40222HurstbourneAttached additions approved under city rules and HOAs
Louisville, KY 40223AnchorageHistoric-district additions with tree preservation plans
Louisville, KY 40243MiddletownAdditions in and around the historic district
Louisville, KY 40299JeffersontownPrimary suites and second stories with J-Town permits
Louisville, KY 40245Lake ForestSunrooms and suites with architectural committee approval
Prospect · 40059Hunting CreekGolf-lot additions and screened porches in Prospect
5.0 from 17 Google reviews
★★★★★
“The addition looks like it was always part of the house. Neighbors ask when we built it.”Home addition, Anchorage Sample text Read our Google reviews
Questions
Home addition questions
Is it better to add on or move?
If you love your location and the lot can accommodate an addition, adding on avoids selling costs, moving and giving up your neighborhood. We'll help you understand what's possible on your lot early in design, before you commit.
How do I know what my lot allows?
Setbacks, maximum height and lot coverage depend on your zoning and form district, and some small cities and HOAs add their own rules. We review your survey and the applicable codes at the start of design.
Can I build an in-law suite or ADU?
Louisville Metro now allows accessory dwelling units in many single-family zones with administrative review. Rules differ in small cities with their own zoning. We'll confirm what applies to your address.
Will an addition match my brick?
We source brick to match size, color and texture as closely as possible, and design the addition so any transition looks intentional. Sometimes a complementary material reads better than a near-miss match.
Do we have to move out?
Usually not. Most of the work happens outside the existing house until the final connection, which we schedule and contain carefully.
How much does a home addition cost?
It depends on size, foundation type, structure, the rooms involved (baths and kitchens cost more than bedrooms) and finishes. See our cost guide and financing options.
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