Fabl Design
Serving Knoxville, TN · Knox County

Architectural design services in Knoxville, TN

Fabl Design plans additions, remodels, ADUs, and custom homes for homeowners across Knoxville and Knox County. We work in the city's Recode zoning districts every day, so we know what your lot will carry before design gets expensive.

Rendering of a house addition with a covered porch in Green Hill, Old Hickory, Tennessee, designed by Fabl Design
100+ home projects designed
Founded 2020
Vetted contractor network
Services

What we do for homeowners in Knoxville

Every service we offer, delivered locally — with drawings your builder and your permit reviewer will both understand.

Find your zoning code

Look up your Knoxville zoning district

Before design begins, confirm the district your lot sits in. The Knoxville zoning map lets you search by street address or parcel number and shows the base district plus any overlays that affect what you can build.

  1. 1Open the Knoxville zoning map and accept the parcel viewer disclaimer.
  2. 2Search by street address or parcel (tax) number to find your property.
  3. 3Note your base district and any overlays, then match them to the standards below.

Zoning maps are for general research only. Verify districts, overlays, and permitted uses with the Knoxville planning department before making decisions — or send us your address and we'll confirm it for you.

Zoning & overlays

Single-family zoning codes in Knoxville

The district your lot sits in sets your setbacks, height, and how much of the site you can cover. Here's a quick reference we use during schematic design in Knoxville.

ENEstablished Residential Neighborhood

Knoxville's oldest, most uniform large-lot neighborhoods. Intended to keep new construction and additions compatible with an intricate, established development pattern.

Min lot
22,000 sq ft
Min width
100 ft (single-family)
Front setback
Within +/- 10 ft of the blockface average, never less than 40 ft
Rear setback
25 ft
Side setback
10% of lot width
Max height
35 ft
Coverage
25% building coverage / 35% impervious
RN-1Single-Family Residential Neighborhood

Traditional low-density single-family neighborhoods on larger lots with generous setbacks. Two-family dwellings only by special use approval.

Min lot
10,000 sq ft (single-family); 15,000 sq ft two-family
Min width
75 ft
Front setback
Within +/- 10 ft of the blockface average, never less than 25 ft
Rear setback
25 ft
Side setback
8 ft or 15% of lot width, whichever is less; 20 ft combined minimum
Max height
35 ft
Coverage
30% building coverage / 40% impervious
RN-2Single-Family Residential Neighborhood

Low-density single-family development on smaller lots with tighter setbacks — the most common infill district in Knoxville's older streetcar suburbs.

Min lot
5,000 sq ft (single-family); 10,000 sq ft two-family
Min width
50 ft
Front setback
20 ft or the blockface average, whichever is less; never less than 10 ft
Rear setback
25 ft
Side setback
5 ft or 15% of lot width, whichever is less; 15 ft combined minimum
Max height
35 ft
Coverage
30% building coverage / 40% impervious
RN-3General Residential Neighborhood

Medium-density neighborhoods of single-family, single-family attached, and two-family homes. Townhouses may be allowed by special use approval.

Min lot
5,000 sq ft single-family; 3,750 sq ft attached; 7,500 sq ft two-family
Min width
50 ft (25 ft per unit attached)
Front setback
10 ft or the blockface average, whichever is less
Rear setback
25 ft
Side setback
5 ft or 15% of lot width, whichever is less; 15 ft combined minimum
Max height
35 ft
Coverage
35% building coverage / 45% impervious
RN-4General Residential Neighborhood

Mixed medium-density residential — single-family, attached, two-family, townhouse, plus low-rise multi-family and pocket neighborhoods by review.

Min lot
5,000 sq ft single-family; 3,500 sq ft attached; 7,000 sq ft two-family
Min width
50 ft (25 ft per unit attached)
Front setback
10 ft or the blockface average, whichever is less
Rear setback
25 ft
Side setback
5 ft or 15% of lot width, whichever is less; 15 ft combined minimum
Max height
35 ft for houses; 45 ft multi-family (35 ft next to a single-family home)
Coverage
35% building coverage / 45% impervious
RN-5General Residential Neighborhood

Medium-density mixed housing that often serves as a transition between single-family blocks and commercial corridors.

Min lot
5,000 sq ft single-family and two-family; 2,500 sq ft per attached unit
Min width
50 ft
Front setback
25 ft or the blockface average, whichever is less
Rear setback
25 ft (30 ft for structures over 35 ft tall)
Side setback
5 ft or 15% of lot width, whichever is less; 15 ft combined minimum
Max height
35 ft for houses and townhouses; up to 55 ft multi-family
Coverage
35% building coverage / 45% impervious
RN-6 / RN-7Multi-Family Residential Neighborhood

Knoxville's highest-density residential districts. RN-6 still permits houses and townhouses; RN-7 is aimed at townhouse and multi-family development.

Min lot
RN-6: 5,000 sq ft single-family; RN-7: 2,000 sq ft per townhouse unit
Min width
RN-6: 50 ft; RN-7: 15 ft per townhouse unit
Front setback
25 ft or the blockface average (35 ft for structures over 35 ft tall)
Rear setback
25 ft (30 ft for structures over 35 ft tall)
Side setback
5 ft or 15% of lot width for structures 35 ft or less; more for taller buildings
Max height
35 ft for houses and townhouses; up to 65 ft multi-family
Coverage
RN-6: 40% coverage / 50% impervious; RN-7: 50% coverage / 70% impervious

Any residential lot not served by sanitary sewer must be at least 20,000 sq ft regardless of district.

Overlay districts to watch for

H-1Historic Overlay

Design-review overlay covering districts such as Old North Knoxville, Fourth & Gill, and Edgewood-Park City, administered by the Knoxville Historic Zoning Commission.

  • Certificate of appropriateness required before a building permit is issued
  • Review of massing, roof form, windows, siding, and porch details
  • Additions expected to be subordinate and set back from the primary facade
NCNeighborhood Conservation Overlay

A lighter-touch design overlay that protects the scale and form of a neighborhood without regulating every material detail.

  • Design review of scale, form, and placement for new construction and visible additions
  • Guidelines adopted specifically for each NC district
HPHillside Protection Overlay

Applies to steep slopes and ridgetops across Knoxville, limiting how much of a hillside lot can be disturbed.

  • Disturbance budget tied to the slope of the land
  • Grading, retaining wall, and drainage detail required with the submittal
  • Slope analysis usually needed before siting the house or addition
IHInfill Housing Overlay

Calibrates new housing in established neighborhoods so infill construction matches the surrounding development pattern.

  • Form standards for height, width, orientation, and garage placement
  • Front setback tied to the existing blockface
FFloodway / Floodplain Overlay

Regulates construction in mapped flood hazard areas along the Tennessee River and its tributaries.

  • Lowest floor elevated above the base flood elevation
  • Elevation certificate required
  • Substantial improvement rules can trigger full compliance on a remodel
ADUAccessory Dwelling Unit standards (Art. 10, § 10.3.B)

Knoxville's standards for a second, smaller dwelling on a residential lot — attached or detached.

  • Maximum size scales with lot area: 600 sq ft (5,000-7,000 sq ft lot), 800 sq ft (7,000-10,000), 1,000 sq ft (10,000-20,000), 1,200 sq ft (20,000+)
  • One ADU per lot, subordinate to the principal dwelling
  • Subject to the base district's setback, height, and impervious limits

These figures are general guidance for early planning — final requirements depend on your parcel, overlays, and any prior variances. Verify with the Knoxville codes department or the official zoning ordinance. We confirm them for your address before design begins.

Recent work

A few Knoxville projects

Two-Story Addition & Front Porch, Pebble Point Estates, TN

Two-Story Addition & Front Porch, Pebble Point Estates, TN

This project expands an existing home with a new two-story addition, larger L-shaped front porch, and new side entry. The addition includes a garage on the lower level and a 340 SF office on the second floor, accessed directly from the existing home's upper level. Matching shed dormers and aligned roof forms bring more natural light, increase usable space, and create a stronger connection between the existing house and the addition. The result is a larger and more functional home that maintains the character of the existing residence.

Whole-Home Remodel & Additions in Franklin, TN

Whole-Home Remodel & Additions in Franklin, TN

This project completely remodels and expands an existing home with a new sunroom, enlarged primary suite, large side addition, and expanded front porch. The design opens up the previously divided interior, creating stronger connections between the kitchen, living, dining, front porch, and backyard. A new garage and workshop take advantage of the site's changing grade, while the additions are carefully integrated with the existing home's scale, materials, and roof forms. The result is a more spacious, connected, and functional home designed to support both the homeowners' current and future needs.

Multi-Level Garage Addition with Connector, El Rancho Estates, TN

Multi-Level Garage Addition with Connector, El Rancho Estates, TN

This project adds a multi-level garage addition to an existing single-family home, connected through a two-story connector that improves circulation between the house, the garage, and the backyard. Responding to the site's changing grade, the design integrates multiple garage levels while introducing a new deck, contemporary material palette, and generous glazing. The result is a functional addition that complements the scale and architectural character of the existing home.

Local process

Permitting & review in Knoxville

Knoxville replaced its old zoning ordinance with the Recode code (Appendix B) in 2020, and Knoxville-Knox County Planning administers it alongside the City's Plans Review and Inspections office. Blockface-average front setbacks, impervious surface caps, and the H-1 historic and hillside overlays drive most residential design decisions here — we confirm all of them before we start drawing.

  1. 1Consultation & measure-up
  2. 2Design set + 3D renderings
  3. 3Builder's set
  4. 4Permit filing assistance
  5. 5Contractor matching & handoff
FAQ

Questions from Knoxville homeowners

Start your project

Designing a home project in Knoxville?

Tell us about your space and what you're hoping to do. We'll write back within one business day.