What You Should Know About the Cost to Build an ADU
Planning to build an accessory dwelling unit (ADU)? These additions are becoming increasingly popular among Denver residents and those in nearby areas. But before deciding on the type, size, and design, you should understand the cost to build an ADU.
The total price depends on many factors. In this article, we’ll break them down for you.
What Affects ADU Cost in Denver, Colorado
Before starting work, consider the following aspects.
- Type of ADU
A detached ADU costs more. It needs its own foundation, utilities, and full construction.
An attached ADU is cheaper because it shares walls and utilities with the main home.
Garage ADU conversion cost can be reasonable, but in Denver, many garages need new insulated foundations. So these can still be expensive.
- Size of the ADU
Bigger ADUs cost more due to more materials, labor, and permit fees. Even small ones need kitchens and baths, which are high-priced per square foot.
- Design, Finishes, and Site Prep
High-end finishes, custom layouts, or energy-efficient upgrades raise the price. Site work like grading, tree removal, or extra utility upgrades add unseen costs.
- Permits, Regulations, and Location
Denver now allows faster building of ADUs by right in many zones, including two-story units; this cuts time and cost. But permits, inspections, zoning, and other rules can still add thousands to the budget.
- Utility Connections
New, detached ADUs often need separate water, sewer, and electricity lines. This can get expensive. The cost to build an attached ADU home will be more pleasant, because all communications have already been installed.
Estimations for Denver Costs
A typical ADU in Denver costs between $230,000 and $310,000. Some projects run higher. Like a detached 600 sq ft ADU can cost in the high $300,000s. It is possible to build a small house for $150-170k. However, in this case, the layout and materials will be the simplest.
Garage ADU Conversion Cost Explained
Many people in Colorado keep renovating their garages. So let's talk specifically about the cost to build an ADU garage.
It is often more affordable than building from scratch, but expenses still vary:
- Larger garages cost more to finish.
- One-story garage - usually the most affordable to convert, starting around $140k+.
- Two-story garage - higher cost, but adds valuable living space or rental potential.
- Design and layout - adding kitchens, bathrooms, or lofts raises expenses.
- Upgrades - insulation, plumbing, and electrical work are often required for older garages.
For a detailed estimate, you can reach out to Arch Design & Build.
Smart Ways to Cut the Cost to Build an ADU House
While your home extension is still in the dream stage, think about how you can reduce future costs. For example:
- Use Pre-Approved Plans. Ready-to-go designs make permitting faster and cheaper.
- Choose a Full-Service Builder. A team that handles design and construction helps avoid delays and extra spending.
- Stick to Essentials. Focus on what you really need instead of pricey custom features.
- Look Into Financing. Options like HELOCs or ADU loans can ease the budget.
- Plan Ahead. Careful scheduling and early decisions prevent pricey changes later.
On our website, you will find even more tips about construction and renovation in Denver and nearby areas. To discuss the future ADU on your property in more detail or to calculate the cost of construction, please contact us.
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