Garage Conversion Drawings · Longmont, CO
Permit-Ready Garage Conversion
Drawings for Longmont, CO
Convert your garage into permitted living space or a rental unit. We deliver complete, code-compliant drawing sets ready for Longmont's building department — in 10 business days, starting at $997.
14-day money-back guarantee · 10 business day turnaround
Local Intelligence
What Longmont Homeowners Need to Know Before Submitting
Size & Zoning Rules
Converting your garage to a legal rental unit means the finished space must comply with Longmont's ADU size limits. Longmont's current ADU size cap is 800 sq ft — within the typical range for most floor plan configurations.
Longmont does not impose an owner-occupancy requirement, so you can rent both the main home and any ADU or conversion as investment units.
A fully permitted, code-compliant garage conversion in Longmont can command approximately $1,495/month as a 1-bedroom rental — far more than leaving the space as storage.
Permit Process & Fees
Building Services Department permit fees for this project type typically range from $5,000 to $10,000 depending on project valuation and scope. Plan check runs approximately 6 weeks — though each correction cycle adds 3–6 weeks, which is why code-compliant drawings matter so much.
Garage conversion drawings submitted to Building Services Department must include a site plan, floor plans, all four elevations, an electrical plan, and energy compliance documentation — plus stamped structural plans are typically required for converted garages that are detached or require seismic upgrades.
Visit Building Services Department ↗Construction Cost Context
Longmont's garage conversion construction costs run $200–$280 per square foot — a moderate range driven by labor markets, local code complexity, and finish level. Our drawings are priced at a fraction of what a full-service architect would charge to produce the same permit set.
⚠ Common Pitfall in Longmont
Longmont's Building Services Department requires a separate sewer tap fee study for most ADUs, since many older lots (especially in the original townsite grid) were platted with single-service lines that can't legally support a second unit without upsizing — this often means an unexpected $4,000-$9,000 tap fee plus a utility locate delay before your permit even gets scheduled for review. On top of that, Boulder County's shared floodplain mapping along the St. Vrain corridor catches more lots than homeowners expect, so if you're anywhere near Fairgrounds Park or the older north-side neighborhoods, plan on an extra elevation certificate step that generic ADU guides never mention. Since STRs are allowed citywide, expect your neighbors to get a mailed notice during permit review — and in practice, that notice period is when most design changes get demanded, not after construction starts.
Expert Verdict — Marcus Reid, Licensed Designer
"In my experience, that $220/sqft and 6-week timeline are Longmont state-level estimates, not gospel — I'd get quotes from two or three local contractors and call the Building Services Department directly before penciling in a budget or start date. I've also seen plenty of "6-week" submittals stretch to 10+ weeks once a plan set comes back with corrections, so build in a cushion, especially if you're relying on that STR income to pencil out the project financially. — Charlotte Pemberton"
Market Context
Longmont has a median home value of $508,000. Comparable renovation projects in this market typically add 23% to resale value.
Neighborhoods in Longmont with the strongest garage conversion and rental-unit potential include Loomiller, Longmont Estates, Sunset, McIntosh, Central Business District (Downtown). Established single-family lots close to downtown make Loomiller ideal for detached ADUs.
Permit Process
Permit applications are reviewed by the Building Services Department, with a plan check timeline of approximately 6 weeks. Permit fees in Longmont range from $5,000 to $10,000 depending on project scope. Design review: Yes - in historic districts only.
Longmont falls within Seismic Design Category Seismic Design Category B, which affects structural requirements for converted garage walls and foundations.
Local Financing Resources
Local Garage Conversion Lenders in Longmont
These lenders offer HELOC, construction, and renovation loans for garage conversion projects in Boulder County. Compare terms before committing.
Offers HELOCs with variable APRs (rates shown starting at 6.99%) and has branches serving Longmont.
Visit Lender ↗Provides land & construction loans including construction-to-permanent options with locally underwritten terms in Colorado.
Visit Lender ↗Offers construction-to-permanent and renovation loans (Fix-It First) to finance building or renovating projects in Colorado, with branch in Longmont.
Visit Lender ↗HELOCs for home renovations with maximum loan amounts cited (example: up to $500,000 / up to 90% CLTV on some products).
Visit Lender ↗Fintech platform (not a direct lender) that partners with credit unions nationwide to offer renovation/ADU financing; check local credit unions for RenoFi-backed products.
Visit Lender ↗Build With A Plan is not affiliated with these lenders. Always compare rates and consult a mortgage professional.
Local Build Partners
Vetted Garage Conversion Contractors in Longmont
We draw the plans. These contractors build the conversion. Independent — no referral fees paid or received.
Build With A Plan provides drawings only. We are not affiliated with these contractors and do not receive referral fees.
Drawing Package Details
What's Included in Your Longmont Garage Conversion Package
Transparent Pricing
Longmont Garage Conversion Drawing Packages
One-time fee. No retainer. No hourly billing.
- ✓Site plan
- ✓Floor plans
- ✓All 4 elevations
- ✓Electrical plan
- ✓Title 24 energy form
- ✓PDF + DWG delivery
- ✓10 business day turnaround
- ✓Everything in Starter
- ✓Structural plans (stamped)
- ✓Cross-section details
- ✓Window & door schedules
- ✓Material specifications
- ✓1 round of revisions
- ✓Everything in Standard
- ✓3D rendering
- ✓HOA submission package
- ✓ADU conversion alt plan
- ✓2 rounds of revisions
- ✓Priority 5-day turnaround
After You Order
Your Conversion Drawings in 3 Steps
Submit Your Garage Details
Share your property address, garage dimensions, and intended use (ADU, rental, home office). We confirm your order and assign your project coordinator within 4 business hours.
We Draft Your Drawings
Our team designs your complete conversion drawing set — engineered for Longmont's building department requirements and CO code. Delivered in 10 business days.
Submit to Your Building Dept
Download your complete package and submit to Building Services Department. We support plan check corrections at no extra charge.
Common Questions
Longmont Garage Conversion FAQs
Is a garage conversion allowed in Longmont? +
Yes — garage conversions are permitted in Longmont. Colorado state law allows homeowners to convert an attached or detached garage into habitable living space or an ADU. A building permit and permit-ready drawings are required before work begins.
How much does a garage conversion cost in Longmont? +
Garage conversions in Longmont typically range from $110,000 to $242,000 depending on the existing structure, finish level, and scope of work. This is significantly less than building a new detached ADU. Our drawing package starts at $997 — a fraction of what a local architect would charge for the same permit-ready set.
What drawings are required to permit a garage conversion in Longmont? +
Longmont's building department requires: a site plan showing the converted garage's location on the lot, floor plans with dimensions and room labels, all four exterior elevations, an electrical plan, and energy compliance documentation (Title 24 in California). Our Starter package covers all of these. If the garage is detached or the structure requires seismic upgrades, stamped structural drawings are also required — included in our Premium package.
How long does the permit process take for a garage conversion in Longmont? +
Plan check in Longmont typically takes approximately 6 weeks. Having complete, code-compliant drawings dramatically reduces correction cycles — which each add 3–6 weeks. Our drawings are designed to pass on the first submittal.
Can I convert my garage into a rental unit in Longmont? +
Yes — a permitted garage conversion can function as a standalone rental unit (ADU or JADU depending on size). In California, converted garages under 500 sq ft qualify as Junior ADUs (JADUs), while larger conversions qualify as full ADUs. Both can be rented long-term. Short-term rental rules vary by city — confirm with Longmont's planning department.
Do I need to replace the garage door opening when converting? +
Yes. The garage door must be replaced with an insulated wall with a standard entry door and at least one egress window (minimum 5.7 sq ft clear opening). This is captured in our elevation drawings and flagged in the electrical plan. The new wall must also meet CO energy code requirements, which we handle in the Title 24 compliance documentation.
How much does it cost to get garage conversion drawings in Longmont? +
Our permit-ready garage conversion drawing packages for Longmont start at $997. Local architects typically charge $2,500–$6,000 for the same set. Every package is engineered for CO code compliance and formatted for Longmont's building department. Turnaround is 10 business days with a 14-day money-back guarantee.
Will converting my garage increase my home's value in Longmont? +
A permitted garage conversion in Longmont adds rentable square footage to a home currently valued around $508,000. Converted spaces typically appraise as habitable square footage, increasing the home's value. As an ADU or JADU, the rental income stream is also capitalized into the appraised value — typically at a 5–6% cap rate.
Nearby Cities
Also Available in Longmont
Need full ADU design drawings instead?
Next Steps
Ready to Move Forward With Your Longmont ADU?
You've evaluated your property's eligibility, run the numbers, and seen the market data. The next step is getting permit-ready architectural drawings to submit to Building Services Department.
Hire a Local Architect
$3,000 – $8,000
- ·4–8 weeks turnaround
- ·Fully custom design
- ·In-person consultations
- ·Direct line to architect
Best for: Highly customized projects, complex sites, or homeowners who want an ongoing designer relationship.
Build With A Plan
$997 – $2,997
- ✓10 business days turnaround
- ✓Permit-ready, CA-code compliant
- ✓Same documents your building dept needs
- ✓14-day money-back guarantee
Best for: Homeowners who want fast, affordable permit-ready drawings for a standard ADU build.
Both options produce permit-ready architectural drawings accepted by Building Services Department. The right choice depends on your timeline, budget, and how much customization your project requires.