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LONE TREE SERVICES

Second-Story Addition in Lone Tree

Licensed second-story addition services for Lone Tree and Douglas County. Double your living space without moving.

What Lone Tree requires

SRL — Front Setback (min): 25' SRL

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Second-Story Addition

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Local Service

Second-Story Addition Services in Lone Tree, Colorado

Autotelic provides professional second-story addition services throughout Lone Tree and the surrounding Douglas County area. Full second-story additions across the Denver metro with structural engineering, framing, roofing, and complete interior build-out. Commercially licensed and insured. Whether you're in Lone Tree (Park Meadows and RidgeGate) or nearby communities, our team delivers quality workmanship backed by Colorado licensing and full insurance coverage.

Permit Thresholds

Lone Tree permit thresholds

Code reference
This aligns with the adopted 2021 International Residential Code (IRC) and amendments (along with other 2021 I-Codes and the 2023 National Electrical Code), as set forth in the City’s municipal code Chapter 18 (Building Regulations).
Building
Fences under 7 feet tall; retaining walls under 4 feet; concrete walks, patios, and driveways; painting; swings/playground equipment; same-size window replacements (like-for-like size; changing opening size requires a permit).
Code reference
Re-roofing generally requires a permit when replacing more than 1 square (100 sq ft).
Code reference
Emergency repairs allow a 24-hour grace period to apply.
Code reference
No use tax, building permit valuation-based tax, or similar rate (with or without a basis such as “applied to X% of valuation”) is specified in Lone Tree’s publicly available building department materials.

Codes are amended regularly — verify current requirements with **The City of Lone Tree Building Division (part of the City of Lone Tree Community Development Department) issues residential building permits.

Zoning & ADU

Lone Tree zoning & ADU quick facts

SRL — Front Setback (min)
25'SRL
SRL — Side Interior Setback (min)
15'SRL
SRL — Side Setback Abutting Street (min)
15'SRL
SRL — Rear Setback (min)
25'SRL
SRL — Building Height (max)
35'SRL
SR-L — Front Setback (min)
25'SR-L
SR-L — Side Interior Setback (min)
15'SR-L
SR-L — Side Setback Abutting Street (min)
15'SR-L
Lone Tree Municipal Code Chapter 16 Art. VII §16-7-290 (Ord. 22-02 Art. 4) SRL setback standards (16-7-290 Development standards of SR-E, SR-L and SR-M) — effective 2022-01-01 · Lone Tree Municipal Code Chapter 16 Art. VII §16-7-290 (Ord. 22-02 Art. 4) SR-L setback standards (16-7-290 Development standards of SR-E, SR-L and SR-M) — effective 2022-01-01Source: library.municode.com

Codes are amended regularly — verify current requirements with **The City of Lone Tree Building Division (part of the City of Lone Tree Community Development Department) issues residential building permits.

Energy Code

Lone Tree energy code quick facts

Code reference
2021 International Energy Conservation Code (IECC) with local amendments (per City of Lone Tree Municipal Code Chapter 18, adopted via Ordinance No. 22-07, Series of 2022).Ord. No. 22-07
Code reference
Lone Tree (Douglas County, climate zone 5B) adopts the 2021 IECC by reference with amendments as part of its building regulations.
Code reference
State law (HB 22-1362 and related provisions) requires jurisdictions updating building codes to adopt at least the 2021 IECC plus the Colorado Model Electric Ready and Solar Ready Code (with amendments that cannot reduce stringency).
Code reference
Key prescriptive requirements relevant to remodels/additions (drawn from the base 2021 IECC for CZ 5B, as specific local numeric energy amendments are not detailed in available municipal sources beyond the general adoption; confirm with the Building Division for exact local tweaks):
Wall insulation
R-20 or 13+5 ci (continuous insulation) for wood-frame walls (2021 IECC Table R402.1.2 or equivalent prescriptive path).
Ceiling/attic insulation
R-49 (2021 IECC Table R402.1.2).
Air leakage/air-sealing
≤ 3 ACH50 (air changes per hour at 50 Pascals) with blower-door testing required for verification (2021 IECC R402.4; state baseline aligns with this).
Fenestration U-factor
Maximum 0.30 for windows (or as per prescriptive table; SHGC requirements also apply in CZ 5).

Codes are amended regularly — verify current requirements with **The City of Lone Tree Building Division (part of the City of Lone Tree Community Development Department) issues residential building permits.

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What a second-story addition covers

A second-story addition in the Denver metro adds habitable floor over an existing house: new floor structure, stairs, roof, windows, and usually electrical, mechanical, and plumbing. The existing foundation and walls have to carry the extra load. A municipally licensed Denver general contractor coordinates the project, design professionals, and licensed specialty trades. Cost is project-specific and depends on structure, roof, and how much of the first floor is opened.

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Structure and zoning height

City and County of Denver Community Planning and Development treats second-story additions as structural review items that exceed IRC prescriptive limits. The residential permitting guide asks for a letter of structural integrity sealed by a design professional who personally inspected the existing foundation and building (DBCA 133.3). Zoning height is measured in feet and stories from the front and rear base planes (Denver Zoning Code Sec. 13.1.2). Plans should show allowed versus proposed height.

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Permits and who coordinates the work

Additions typically need zoning, building, and Sewer Use and Drainage (SUDP) reviews, plus electrical, mechanical, and plumbing when those systems change. Denver Energy Code Chapter 5 [RE] applies to additions. Cities and counties license general contractors. Colorado has no statewide general contractor license. Autotelic acts as a municipally licensed Denver general contractor and coordinates licensed specialty trades plus the design professionals required for the project.

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What buyers should prepare

Target rooms, existing drawings if any, roof and attic photos, and known foundation concerns.

FAQ

Common questions

Do second-story additions need a Denver permit?

Yes. CPD requires building, zoning, and typically SUDP, with structural review because the work exceeds IRC prescriptive limits.

Who handles second-story permits and licensing?

A municipally licensed Denver general contractor coordinates the project, design professionals, and specialty trades. Colorado has no statewide general contractor license.

Can the existing foundation take a second story?

Only after a design professional inspects it. CPD asks for a sealed structural-integrity letter for second-story additions.

How is height measured?

In feet and stories from the zoning front and rear base planes, not just from the sidewalk.

What information helps define scope?

Desired rooms, existing drawings, foundation notes, landmark status, and city or county.

Service Area

Serving Lone Tree and Douglas County

We serve Lone Tree, CO and all surrounding Denver metro communities. Our team is based in Denver and operates throughout the Front Range, from Castle Rock to Longmont and everywhere in between. Contact us for a free estimate on your Lone Tree project.

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