Planning to finish your basement in Northern Colorado? Before framing walls, installing new wiring, or adding a bathroom, you will generally need a building permit in the municipalities covered here. The amount due depends on the jurisdiction, project valuation or finished area, and the scope of electrical, plumbing, mechanical, structural, and tax-related charges.
Some municipalities publish a flat building permit fee for a basement finish. Others calculate a permit fee from project valuation, then add plan review, trade, administrative, or use-tax charges.
This guide explains how basement-finish permitting works in Fort Collins, Loveland, Berthoud, Longmont, Erie, Boulder, and Windsor, and uses a real 2026 Loveland permit to show how the charges can add up.
Last verified: October 23, 2026. The figures below are from official municipal pages, fee schedules, and permit reports available on that date. Most 2027 schedules were not yet published, so applicants should verify the schedule in effect when they apply.
Table of Contents
How Much Does a Basement Finishing Permit Cost?
There is no single basement-finishing permit price across Northern Colorado.
For example, Fort Collins currently lists a $155 building permit fee for a residential basement finish, plus sales tax calculated from the project's total valuation. Berthoud uses a valuation-based building permit fee and separately lists a $100 basement-finish plan-review fee, plus $50 administration and $50 technology fees. Loveland's public records show how building, plan-review, trade, and city-and-county tax charges can combine into a larger municipal total.
The important distinction is between a basic building permit fee and the total permit-related charges assessed for a particular project.
Basement Finishing Permit Costs by City
| City | Verified 2026 fee information | What homeowners should know |
|---|---|---|
| Fort Collins | $155 residential basement-finish building permit fee | Sales tax is calculated from total project valuation; structural window work may change the required submittals |
| Loveland | Project-specific | Building, plan-review, electrical, mechanical, plumbing, and city-and-county tax charges may apply |
| Berthoud | Valuation-based building permit; $100 basement-finish plan review; $50 administration; $50 technology | The current worksheet values an existing-home basement finish at $80 per square foot; other applicable charges may be added |
| Longmont | Project-specific amount provided after plan approval | Submit the residential remodel/addition application and a dimensioned, labeled floor plan |
| Erie | Basement-finish valuation basis of $38.72 per square foot | The valuation is used to calculate the building permit fee; the 2026 memo says no separate plan-check or residential trade-permit fees are added for a basement finish, although separate structural/remodel work can add permits and fees |
| Boulder | Valuation-based building fee using a 50% basement-finish scope factor | A single-family plan-check fee, construction use tax, and applicable electrical, mechanical, and plumbing fees are separate |
| Windsor | Project-specific estimate available from the Town | A basement finish requires a permit; the Town publishes a basement-finish handout and provides estimates after applicants submit its estimate form |
Fort Collins: The current Building Permits page lists a $155 building permit fee for a full or partial residential basement finish. It also says sales tax is calculated from the project's total valuation, meaning materials and labor. Structural work, including a new or enlarged basement window that cuts the foundation wall, requires an engineer's evaluation letter.
Berthoud: The 2026 schedule keeps the building permit valuation-based under the referenced code table, lists a $100 basement-finish plan-review fee, and says $50 administration and $50 technology fees are added. The residential estimate worksheet uses $80 per square foot for a basement finish in an existing home and lists other potentially applicable items, including electrical fees and town and county use tax. Not every line on the general worksheet applies to every basement project.
Longmont: The City requires a residential remodel/addition application and a full basement floor plan with dimensions and room labels. The plan reviewer provides the permit-fee amount after the plans are approved. An approved plan set must remain on site for inspections.
Erie: The Town's 2026 valuation memo assigns basement finishes a valuation of $38.72 per square foot. That figure is not the permit price; the valuation is applied to Erie's building-permit fee table. The same memo says a basement finish does not receive a separate plan-check fee or separate residential mechanical, electrical, and plumbing permit fees. Structural changes, new exterior openings, water-heater or furnace replacement, and other separately scoped work can require additional permits or fees.
Boulder: The 2026 schedule values a residential basement finish at 50% of the applicable residential construction value. The City uses the higher of its valuation-table result or the applicant's estimated value to calculate the building permit fee and estimated construction use-tax prepayment. For a typical single-family residential application, the initial plan-check fee is 25% of the building permit fee. Applicable electrical, mechanical, and plumbing permit fees are separate.
Windsor: The Town states that finishing a basement requires a building permit, even when the homeowner performs the work. Its Building Permits page provides a basement-finish handout and an estimate-request process rather than publishing one universal basement-finish price.
Official municipal references are linked in the Sources section.
Real-World Example: A Lefort Built Basement Permit in Loveland
Loveland's February 2026 permits-issued report lists residential basement-finish permit BP-26-00195, issued February 13, 2026, with Lefort Built LLC as the contractor.
The recorded scope was:
- 1,193 square feet of basement finishing
- One bedroom and one bathroom
- A great room and wet bar
- A craft room
- Replacement of windows to meet code
- 152 square feet remaining unfinished
What Did the Municipal Report List?
| Charge | Amount |
|---|---|
| Building permit | $542.75 |
| Plan check | $352.79 |
| Electrical permit | $83.25 |
| Mechanical permit | $69.25 |
| Plumbing permit | $83.25 |
| City use and county tax | $810.00 |
| Total documented municipal charges | $1,941.29 |
The amounts above match Loveland's February 2026 Permit Fees Paid - Detail report.
The arithmetic also checks:
- Plan check: $542.75 x 65% = $352.7875, rounded to $352.79.
- City-and-county tax base: 50% of the $40,000 permit valuation = $20,000.
- Rate represented in the report: 3.00% Loveland + 1.05% Larimer County = 4.05%.
- Tax: $20,000 x 4.05% = $810.00.
- Total: $542.75 + $352.79 + $83.25 + $69.25 + $83.25 + $810.00 = $1,941.29.
Loveland's report labels the $810 line City Use & County Tax. It should not be described as including Colorado's separate 2.9% state tax.
The City recorded a permit valuation of $40,000. That is the valuation shown in the municipal permit record; the reports do not disclose the homeowner's final construction price or Lefort Built's contract amount.
What this example demonstrates: A basement permit can involve more than the building permit fee alone. Plan review, trade work, and applicable taxes can materially affect the municipal total.
What Makes Up Basement Permitting Costs?
Building permit fees
The building permit covers municipal authorization and inspection of the proposed construction under the adopted codes. Depending on the jurisdiction, it may be a flat amount or calculated from valuation.
Plan-review fees
A building department may review floor plans, room uses, framing, insulation, egress, and other construction details before issuing a permit. Some municipalities charge separately for that review; Erie specifically says not to add a plan-check fee to a basement finish under its 2026 methodology.
Electrical, plumbing, and mechanical charges
New outlets, lighting, bathrooms, heating, ventilation, or gas work can affect permit scope and fees. Whether those items appear as separate permits or fee categories depends on the jurisdiction. Erie, for example, includes residential trade-permit fees within a basement-finish project under its 2026 methodology, while Loveland's public report lists separate electrical, mechanical, and plumbing fee columns.
Construction use taxes and additional fees
Municipalities may collect estimated tax on construction materials, often using a percentage of project valuation as the estimated material value. Administrative and technology fees may also apply. Ask for an estimate of total permit-related charges, not only the building permit fee.
Is a Permit Required for a Basement Finish?
In each municipality covered by this guide, finishing an unfinished basement generally requires a building permit. The work commonly involves regulated framing, electrical systems, insulation, and sometimes plumbing, mechanical, structural, or exterior-opening changes.
Purely cosmetic work can be exempt in some jurisdictions. Fort Collins and Erie, for example, list painting, floor coverings, cabinets, and similar work among permit exemptions, but concealed wiring, new plumbing, structural changes, and other regulated work are not covered by those cosmetic exemptions.
Confirm requirements with the authority having jurisdiction for the property's exact address before work begins.
How Does the Basement Permitting Process Work?
Procedures differ by municipality, but a typical project follows these stages:
1. Prepare the proposed floor plan. Identify room dimensions and uses, doors, windows, stairs, mechanical equipment, and other required details.
2. Submit the permit application. Provide the required application forms, plans, and supporting documents.
3. Complete plan review. The building department evaluates the submittal and may request revisions or additional information.
4. Obtain permit approval. Pay assessed fees and receive authorization before beginning work that requires a permit.
5. Schedule required inspections. Depending on scope, inspections may include underground plumbing, rough electrical, rough plumbing, rough mechanical, framing, insulation, and final inspections.
6. Complete final approvals. Resolve required corrections and confirm that the permit is closed.
Longmont note: An approved plan set must be on site for inspections.
Common Basement Permitting Mistakes
Starting construction before receiving approval
Starting regulated work before permit issuance can lead to delays, correction work, and penalty fees. Boulder, for example, states that several permit fees are doubled for work started or completed without an approved permit.
Assuming every city has the same rules
Berthoud, Loveland, Longmont, Fort Collins, Erie, Boulder, and Windsor use different fee methods and submittal requirements.
Overlooking bedroom and egress requirements
A sleeping room requires a compliant emergency escape and rescue opening where the adopted code applies. Erie also requires at least one operable emergency escape and rescue opening in the finished area when no sleeping room is proposed. New or altered exterior openings can trigger structural engineering and a separate permit or fee.
Forgetting trade scope
Electrical, plumbing, mechanical, gas, or appliance work can change the required permit documents, inspections, and fees. How those charges are packaged differs by municipality.
Confusing permit valuation with construction cost
Municipal valuation is an administrative basis for calculating fees and taxes. It is not necessarily the contractor's price, the homeowner's final cost, or the property's market value.
Frequently Asked Questions
Rules vary. Erie requires a homeowner affidavit when a homeowner performs any of the work and limits eligibility to a person who owns and occupies the property as a primary residence. Other jurisdictions have their own homeowner and contractor requirements.
Typically, yes. A new bathroom involves plumbing and usually electrical, ventilation, and building work. The permit structure and fees depend on the municipality.
It can. A sleeping room must meet applicable emergency escape and rescue opening, alarm, ventilation, light, and other life-safety requirements.
Review times vary with the jurisdiction, completeness of the submittal, workload, and required revisions. Ask the local building department for its current review estimate.
The owner may need after-the-fact review, inspections, corrections, and additional fees. Unpermitted work can also complicate later renovations or property transactions.
Possibly. As of October 23, 2026, most 2027 municipal schedules cited by this guide were not yet available. Verify the schedule in effect on the application date.
Planning a Basement Finish in Northern Colorado?
Basement finishing involves more than choosing a floor plan and finishes. Permit requirements, inspections, code compliance, and coordination among trades all matter.
At Lefort Built, we help homeowners plan and complete basement-finishing projects throughout Northern Colorado.
Whether you are considering a family room, guest bedroom, home office, wet bar, or another living area, identifying permit requirements early can help keep the project organized.
Official Government Sources
- City of Fort Collins: Building Permits - Basement Finish
- Town of Berthoud: 2026 Schedule of Rates, Charges and Fees
- Town of Berthoud: Residential Building Permit Fee Estimate Worksheet
- City of Longmont: Basement Finishes
- Town of Erie: Residential Basement Finish
- Town of Erie: 2026 Project Valuations to Determine Building Permit Fees
- City of Boulder: 2026 Planning and Development Services Fee Schedule
- Town of Windsor: Building Permits
- City of Loveland: Building Division Data and Reports
- City of Loveland: February 2026 Permits Issued
- City of Loveland: February 2026 Permit Fees Paid - Detail
- City of Loveland: 2026 Fee Schedule
- City of Loveland: Construction Use Tax
- City of Loveland: 2026 Larimer County Tax-Rate Announcement
