In the Know

Home / In the Know / What is a U-Value and why does it matter for steel doors?

What is a U-Value and why does it matter for steel doors?

Riverside Enterprise Park Lincoln3

A u-value measures how efficiently a building element reduces heat loss. Lower is certainly better when it comes to a U-value. The lower the value, the more effective it is in keeping the warmth in and the cold out.

It’s not only steel doors which have thermal properties measured by a U-value, every building is made up of lots of elements, each with their own U-values. All these elements will combine together to give the overall thermal insulation performance for the building.

Another advantage of a thermally rated door, is that it reduces the chance of condensation building up on the inside of the leaf.

 

What U-Value do I need for my Steel Doors?

Depending on the application for a project, your required thermal rating/ U-value will be different.

For example, if you are looking for a steel door used in an office with people inside, keeping the heat in is key! In this application, we would recommend a Rockwool core which has a U-value of 1.9 or our Climador range with an even lower U- value of 1.6 (Don’t forget the lower the number the better the insulation value).

Whereas if you are installing a steel door in an unheated space, the thermal rating may not be as important, therefore our standard honeycomb core could be most suitable.

 

Are there any legal requirements for minimum ratings?

Yes, depending on the application there are regulations which will state the minimum U-value required for new dwellings and commercial buildings. Steeldor thermal was developed to comply with these door efficiency targets stipulated by the government in The Building Regulations 2010. The leaf has an insulated, internal Rockwool core enabling it to achieve a U-value of 1.9, compliant with the guidance of 2.0 for new dwellings and 2.2 for new commercial buildings. These door-sets meet the standards set out in the 2010 approved documents L1A and L2A.

We always recommend that you check with your building regulation compliance inspector to ensure you are specifying the correct U-Value for the use of the building.

Related Content

Red Nose 2

Red Nose Day 2023 Strongdor raise over £500 for Comic Relief!

Strongdor raises £547 for Comic Relief with various fun activities, bake sales and customer selfies.

View Article
Tracey Spotlight Mobile

The faces behind Strongdor – A spotlight on Tracey

Strongdor is dedicated to shining the light on their hard-working team who help keep the company known for impeccable customer service. In this article, we hear Tracey's insights into what it’s really like working for Strongdor.

View Article
Fire Classification Banner Mobile

When is a fire-rated door required and how do I specify one?

Fire-rated doors are extremely important as they help prevent the spread of fire, resulting in them always being required. Holding back flames from a trapped person who is trapped within a building allows greater time for the emergency services to reach the area and save lives.

View Article

Why Strongdor?

I3

Industry beating lead times

I2

Steel door experts

Strongdor Icons Fast Quotes

Fast quotations

Strongdor Icons Security

Secured by steel

Strongdor360
Ti

360 Interactive Tour

Step inside the Strongdor factory and discover how our doors are made!

Take a 360 Virtual Tour
Sp1

Get an expert quote

Get expert advice and a free quote with no obligation

Request a Quote

Technical help

Search our knowledge bank of tech specs, fitting guides and more

Visit our Knowledge Bank Sp2

Customer Reviews

DoorBook

Our latest brochure

Doorbook Hexagons

Projects

Our range of high-quality steel doors have been used across the country

Stay connected

Follow us on social media facebook icon twitter icon linkedin icon instagram icon

Trade customer?

Purchase steel doors regularly? Speak to one of our account managers and request to set up an account today.

Apply today

Stay in the know

Join our mailing list for industry news, product updates and more