Room Addition
Bump-Outs, Room Additions, Pop-Tops & Second-Story Expansions Across the Denver Metro & Front Range
Add the space your family needs without moving. PrimeStone Construction Group is a licensed, structural engineer–owned room addition contractor building bump-outs, single-room additions, and full second-story pop-tops throughout Denver, Aurora, Lakewood, Boulder, and the greater Front Range. Because additions tie into your existing home, structural engineering isn’t optional — and it’s exactly what we do best.
A room addition expands your home’s living space by building outward (a bump-out or ground-level addition) or upward (a second-story addition or pop-top). It ties into your existing structure and can add a bedroom, home office, primary suite, sunroom, or an entire second floor.
Types of Room Additions We Build
Bump-Out Addition
A small expansion of an existing room extending a kitchen, adding a breakfast nook, or enlarging a bathroom. The fastest and most affordable addition type.
Ground-Level Room Addition
A full new room built outward on your lot a bedroom, home office, family room, sunroom, or primary suite. Requires foundation work and ties into your existing home.
Second-Story Addition / Pop-Top
A complete second story added to a single-story home. Pop-tops are popular in lot-constrained Denver neighborhoods (Wash Park, Platt Park, Park Hill) because going up keeps the yard intact and leverages your existing foundation and valuable land. This is the most structurally complex addition.
Primary / Guest Suite Addition
A larger addition creating a full suite bedroom, bathroom, and often a walk-in closet for a growing family, multi-generational living, or resale appeal.
Room additions in Denver typically cost between $18,000 for a small bump-out and $500,000+ for a large second-story addition in 2026. Ground-level additions generally run $80–$200 per square foot, while second-story additions and pop-tops run $200–$500 per square foot due to added structural, plumbing, electrical, and permitting complexity.
Addition Type | Estimated Cost (2026) | Cost per Sq Ft |
Bump-Out | $18,000 – $36,000 | — |
Ground-Level Room Addition | $95,000 – $200,000 | $80 – $200 / sq ft |
Second-Story / Pop-Top | $200,000 – $500,000+ | $200 – $500 / sq ft |
Primary / Guest Suite | $150,000 – $380,000 | varies by scope |
Key Colorado cost drivers:
- Structural reinforcement: Second-story floors need new joists and LVL beams; foundations may need strengthening often tens of thousands of dollars.
- Snow load & insulation: Denver additions require snow-load framing plus R-38+ attic and R-19+ wall insulation adds roughly $8,000–$18,000.
- Energy-code windows: Colorado requires high-performance windows (U-factor ≤ 0.30); quality packages add $4,000–$12,000.
- Electrical service: An addition may require a panel/service upgrade, especially in older homes.
PrimeStone provides a detailed, itemized estimate that separates structural, mechanical, and finish costs before construction begins.
Most room additions in Denver take 3 to 6 months, while a full second-story pop-top typically runs 10 to 14 months from signed contract to completion. Denver permitting for a pop-top (a Major Residential Project) commonly takes 6–10 weeks, and 8–12 weeks in historic neighborhoods like Wash Park with LPC review.
Addition Type | Typical Timeline |
Bump-Out | 4 – 8 weeks |
Ground-Level Room Addition | 3 – 6 months |
Second-Story / Pop-Top | 10 – 14 months |
For a second-story addition, most families move out during active framing the 2–4 week period when the roof is off and the new floor and walls go up. Budget roughly $3,000–$5,000 per month for temporary housing during that window. Once the structure is weather-tight, you can typically move back in and live through the finishing phase, with some noise and dust.
Permits & Code for Denver Room Additions
Room additions require building, electrical, plumbing, and mechanical permits from Denver Community Planning & Development. Pop-tops are classified as Major Residential Projects with a longer review. Additions must respect setbacks, bulk plane, and lot-coverage limits, and meet snow-load and energy codes. Older homes may need electrical panel upgrades. PrimeStone manages the full permit process and engineers all structural work in-house.
Our Room Addition Services
PrimeStone provides full-service room addition solutions from concept and design to construction and final inspection.
PrimeStone provides full-service room addition solutions from concept and design to construction and final inspection.
Because PrimeStone is structural engineer–owned, all room additions undergo an engineered review to ensure proper load paths, structural integrity, and building code compliance.
Our Room Addition Process
We begin with an in-home consultation to understand your space, needs, and goals. Our team evaluates existing structures, foundation conditions, and feasibility.
We develop architectural plans, structural engineering details, and permit-ready drawings to ensure safety, compliance, and functionality.
We handle all interactions with local authorities — submitting plans, securing permits, and coordinating inspections.
From foundation to finish, we deliver high-quality construction, structural framing, and detailed craftsmanship.
We ensure all inspections are passed, code requirements are met, and your newly expanded living space is ready to be enjoyed.
PrimeStone combines structural expertise with construction excellence, giving you a room addition that not only looks great but performs safely and reliably for years to come.
Ready to expand your home?
Contact PrimeStone today to schedule a consultation and receive a detailed estimate for your room addition project.
Room Addition FAQ
What types of room additions can you build?
Do I need a permit for a room addition in Colorado?
How long does a room addition take?
How much does a room addition cost?
Will the addition look like part of my existing home?
Do you handle structural engineering for room additions?
What if my house has foundation limitations?
Do you manage subcontractors and inspections?
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