Frequently Asked Questions

Build it faster, stronger, warmer and smarter

Frequently Asked Questions

Here are answers to the most frequent questions we’re asked.

If there’s anything you need to know, please call us on 0330 166 0877 or email

What’s included in an Extension Kit?

We design manufacture & Supply SIP Kits under our brand names Extension Kitz & SIP Kitz. We also manufacture ‘Offsite Retail Pods’, so our kit content will differ due to the bespoke nature of the product. As a general rule, we will provide EVERYTHING you need to build your chosen Kit. Please visit this link to find out more.

Will I need planning permission?

Some home extensions will not require planning permission and will fall under Permitted Development rights, depending on their size. Please seek guidance from your Local Planning Authority, or contact us by telephone on 0330 166 0877 or email if you are at all unsure.

Are Extension Kits compliant with current building regulations?

All of our Extension Kits comply with current building regulations. Thermally & Structurally.

What types of external finish are available?

We can supply,

  • Brick slips,
  • uPVC Cladding,
  • Timber Cladding,
  • Aluminium Cladding,
  • Ceramic Tile,
  • Cement Board,
  • Render

More options are available, for more info please email our sales team at

Are electrics included?

We can supply Consumer Boxes, electrical cable, lights, sockets and switches.

Is a SIP extension kit strong?

Very strong is the answer! SIP Buildings are actually 3 x stronger than brick build, 7x stronger than stick / timber frame buildings.

How long does it take to build an Extension Kit?

Typically one of our kits can be built and ‘dry’ within 2-3 days – with the whole process from start to finish taking around 3-4 weeks.

What is a typical lead time?

The typical lead time from placing the order until delivery to the site is usually 10-15 days from receiving a signed order.

How do I pay for my Extension Kit?

Payment should be made in full at the latest 24 hours before dispatch of your kit. Methods of payment we accept are:

  • Cash
  • Debit / Credit card
  • Bank Transfer

Why build with SIPs?

Why should I build with SIPs?

  • They offer a speedy build
  • Energy efficiency & Low U-values,
  • Excellent air-tightness,
  • Exceptional Design flexibility,
  • Maximises living space which ultimately adds value to your home.
  • Confidence knowing you are buying an engineered product which is factory produced and is backed by our comprehensive warranty.
  • 3x Stronger than Brick Build
  • 7X Stronger than Timber frame / Stick build

What do you need to do to insert the flue for a wood burning stove?

The flue must be double lined with a 15mm gap around this and then packed with fireproof corking.