Is it legal to finish an attic?

Author: Cleta Kunde MD  |  Last update: Tuesday, December 23, 2025

Understand Building Codes If your goal is to sell your home at some point, you must follow local building codes and finish your attic so that it's considered a legal liveable space. While the specific rules vary by location, most codes require a finished attic to be: At least seven feet wide. At least seven feet high.

What are the rules for finishing an attic?

The 7 and 7 rule for attic conversions refers to the common requirement that finished attics be at least 7 feet wide and 70 square feet, with 7-foot ceilings over at least half. Keep in mind that this is a general guideline. Local building codes may have stricter requirements that supersede this rule.

Do you need permission to convert an attic?

A loft conversion for your house is considered to be permitted development, not requiring an application for planning permission, provided certain limits and conditions are met.

Is it OK to finish an attic?

In most cases, yes. Adding living space to your home typically requires a building permit, and this includes finishing an attic. However, the specific requirements for permits vary depending on your location, so it's best to check with your local building department.

How do I know if my attic can be finished?

Here are a few standard requirements to check first. If you plan to make your attic space livable, it needs to meet the typical seven-foot ceiling height or clearance in a minimum of a seven-foot wide space–after finishes are installed!

Things you must consider before attempting an attic to living space conversion

What is the 7 and 7 rule for attics?

This rule means, at least half of your attic space must be 7 feet high by 7 feet wide, with a total of 70 square feet. Keep in mind, codes vary from place to place, but for using the attic as an actual room, this rule typically applies.

Is it expensive to finish an attic?

Finishing an attic generally costs between $30 and $60 per square foot, including labor and materials. This gives you an average overall cost of $4,000 to $16,000 for the standard sized attic. Of course, the cost depends on how big your attic is and what type of finish you want.

How do you know if your attic can be converted?

The Five Signs That You Can Convert Your Attic
  • Building Code Compliance.
  • Suitable Architectural Style.
  • Efficient Insulation.
  • Functional Electricity and HVAC Systems.
  • Proper Ventilation.

What is the difference between a finished attic and an unfinished attic?

Finished attics are usually climate-controlled and have flooring, ceilings and walls making them more suitable for conventional use. Traditional attics, being unfinished, are typically not suited for conventional use as you can see the insulation, rafters, and beams within the space.

Can attic trusses be removed?

Removing trusses without proper planning and execution can lead to severe structural damage, including the collapse of the entire roof. The integrity of ceiling joists and other supporting structures may be compromised, risking not just the roof but also the overall stability of the building.

How do I make my attic a legal bedroom?

Regulations vary from county to county, but most attic conversion building codes require:
  1. A minimum of 70 sq. ft. ...
  2. At least 7 ft. in each direction. ...
  3. At least 50% of the ceiling should be a minimum of 7.5 ft high. ...
  4. A sturdy, full-size staircase. ...
  5. Windows.

Can I turn my attic into usable space?

Converting an attic into a usable room is a great way to increase the functionality of your home as well as its appeal to future home buyers. We've worked with clients to convert their attics into all manner of things, including: Additional bedroom(s) Granny units.

Are attic bedrooms legal?

An attic can make a perfectly good bedroom as long as it meets ceiling height requirements and has an acceptable window. A former living room or den is also often a good candidate for a bedroom, since it likely has methods of egress and meets other requirements already.

What is the building code for a finished attic?

Here's a quick summary of what most local building codes require: Floor Space: finished attic spaces should be at least 70 square feet. Width: the living space should be at least 7 feet wide or long. Ceiling Height: at least 50% of the room's usable space needs a clearance that's 7 feet high.

Can you count a finished attic as a bedroom?

There has to be heat and ventilation. The room must be finished (electrical, insulation, wallboard, etc.). So yes, it can be legal at some point. You can't just put a bed up there and call it a bedroom.

Can I over insulate my attic?

While over-insulated attics aren't as common as under-insulated attics, it is possible to put so much insulation in your attic that it has a negative impact.

Is it okay to finish an attic?

By adding insulation and improving ventilation, finishing your attic can improve your home's energy efficiency. This can help you save on energy costs and create a more comfortable living space for your family.

Why are most attics unfinished?

Not all attics have the potential to be finished. That's because they must be at least 70 square feet overall and measure at least 7 feet in any direction (to be up to code). If a room has a sloped ceiling (which is pretty common in attics) at least 50% of the room area has to have a 7-foot ceiling (2).

How do you determine if an attic can be finished?

For your attic to be a good candidate for attic conversion, its habitable space must first satisfy the requirements that govern the other rooms of your home. The attic must be at least 70 square feet, while the attic ceiling must be five feet or higher. Windows & openable area.

Do I need a permit to finish my attic?

Reach out to your local municipality to see if you need a permit for your attic remodel. A permit is usually only needed if: You are adding electrical wiring or ventilation. You plan to change the structure of your home in the process, such as knocking down an existing wall or adding a dormer.

Which lofts cannot be converted?

Moreover, houses built during or after the 1960s may have trussed roofs, which are characterised by their 'W' shaped frames that support both the roof and the floor. These trusses are not designed with loft conversion in mind, as altering them is a complex process that requires replacement with sturdier supports.

How much does it cost to finish an attic?

Attic finishing may include framing, drywall, insulation, subflooring, a fan and more. You can expect to pay $5,000 to $20,000 to get your attic to this level, and more depending on what you want to do with it.

How much is a full attic conversion?

The average loft conversion costs between £20,000 to £60,000 in the UK. The price of a loft conversion varies widely based on the type of loft conversion you have, the quality of materials used, and the labour costs in your part of the UK. The average cost of a Velux loft conversion is between £20,000 to £30,000.

What is the R value of a finished attic?

Most building codes require a specified minimum amount of headroom. It's often tough to meet this requirement when insulating a finished attic, especially since most codes require insulation equal to R-38 or more.

Does an attic conversion add value?

Attic conversion

This is probably the easiest way to add extra living space and a bathroom to your property without causing too much disruption, and can typically add around 12-15% to your property's value.

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