DTW Chimney Design (design free, prices for example only)

Size and complexity

Let us design your clip-together twin wall chimney for you. Free service.

Shed, shack, boat, van?

Need a simple 3-metre chimney for a shed, shack, caravan, boat, home office or van? This is so simple we have just the product for you here

Or we can design your chimney for your unique property. Read on ...

DIY? Read our in-depth installation guide

The service (within 5 working days)

We have been designing twin-wall chimney systems since 2007 (in winter we will often do 5-10 designs a week).

We use our own twin-wall design software which is accurate to within millimetres.

We strive to make the procedure as simple & stress-free as possible.

We do not install but find one of our listed and registered installers.

Peace of mind

Design process includes any design changes as required should the need arise.

Telephone support during all stages including installation phase.

We do not charge for the design process - just for the parts.

All scenarios available by clicking below. Get your quote now! 5-7 days turnaround

There is no obligation to purchase. We care that you are pleased with the service but do not worry if you do not purchase. I (Julian) personally create or oversee (with colleague Ray) all drawings and send a drawing and quote and then forget about you unless you make contact :-) We don't keep tabs on who orders and who does not. Our job is to give you a great quote and drawing.

Variants (chimney outside property): a few examples

You can see these in more detail on this page

Variants (chimney inside property): a few examples

You can see these in more detail on this page


All parts are Duraflue, a premium brand as chosen by many UK installers.

Easy-fit bracketing system.

Black or silver - you choose.

All chimneys on this page were self-installed by customers.


Fast turnaround within 5 working-days.

Please check out our reviews at the foot of this page.

What is included?

Included is everything you need to do the job and if something is optional this will be stated in your quote.

Wall brackets are included on external systems but not in internal systems (floor plates used where appropriate here).


A rough guide (silver 5"):

Shed £425-£500 (if out through roof)
Bungalow internal £600-£900
Bungalow external £800-£1100
Two-storey house internal £800-£1000
Two-storey house external £1000-£1400

Extension but chimney attached to main house £1200-£1500
Extension but chimney separate to main house £500-£700 (if out through roof)

Black add 20%. 6" add 10%


Don't worry if your property differs from the norm - often we can make it work.


Building regs

Designed and checked to UK building regulations standard by Julian Patrick, author of the Stovefitter's Manual.

Note from Julian (author, Stovefitter's Manual): BEWARE of cheap designs from some companies - they often use inferior materials and often do not know their regulations - leading to failed sign-offs and raised stress levels.

Video: simple guide to chimney design rules

Trade reviews


Review by Hetas registered installer D. Parker: Firstly – Dura Twin Wall is brilliant to use and the kit is absolutely fantastic! Better than Dinak and Poujoulat. Will be doing a brilliant review once finished.

Review by Leon - ELB Fireplaces: The products are the best I've ever used. The flue liner is extremely strong and with its multi direction flow it's perfect. The Duratwin twin wall is for me their best product with its push together system not twist and lock it makes life an installer that bit more easier. It has reduced the installation time which is a big bonus to any company and with the sleek black finish it just finishes the job perfectly. I would advise any company to give it a try.

NUTEC Stove & Kitchen Company Ltd : We have now used Duraflue Twinwall on 5 jobs and continue to be impressed with both the sturdy design as well as the quality of fit, especially when compared to other models available. We have just about used part and will continue to do so going forward as nothing comes close. Really impressed with Julian and Arran who constantly look after us.

Customer Reviews

Based on 190 reviews
Bruce Coker
Excellent experience

Couldn’t have been mmore helpful, from trying to resolve my delivery requirements to patiently answering my many questions.

Excellent communication, always prompt and friendly – and the website is a mine of information for anyone contemplating a DIY stove installation. I’ve fitted a lot of stoves, in a lot of different situations – houses, vans, trailers, boats – but I still learned a vast amount from SW’s extensive documentation.

As a bonus, I really appreciated being able to get everything I needed for my current project from one place.

Would definitely use again.

David W
Great kit

Purchased the flue kit with help from the team at stovefitters. Excellent service and help throughout. Had to buy an additional section to finalize the install and it was delivered quickly and for free. Cannot fault the service or the product, thank you!
Kit is fantastic, excellent quality and well made. Highly recommend using stovefitters for any stove installation. Looking forward to figing up the stove this winter!
Order #13063