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4M X 3M(D) Self Build Insulated Garden Room

£11,997.97 £7,999.97

You save: £3,998.00 33% Off

Free Installation Service (Wooden Buildings).
Free Insured Shipping.
10 Year Anti-rot Guarantee.
Manufactured in the UK.
Reasonable Price

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Delivery Truck Made to Order: Ready in 3-5 days, Arrives within 5 days.

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What size is this self build garden room kit?

This is a 4m x 3m insulated garden room with internal space of 4m x 3m. It suits searches for 4 x 3 garden room, 4m x 3m garden office, and 4m x 3m garden room. The imperial size is 14 x 11.

Is this a flat pack garden room I can build myself?

Yes, this is a self build garden room kit delivered flat pack. It’s a garden room self build option with instructions. Perfect for diy garden room kit enthusiasts wanting a self build insulated garden room.

What insulation does this fully insulated garden room have?

It has 72mm thick double skinned walls, double glazed garden room windows, and fully insulated roof, floor and walls. This insulated garden room works as an insulated garden bedroom or insulated outdoor room all year.

Can I customise the doors and windows?

Yes, the modular design lets you place doors and windows to suit your needs. This is a key feature of kit garden rooms and garden room kits like this self build garden room kit.

What base do I need for this self build garden room?

A firm, level base is required. Consider an insulated concrete base for garden room or solid concrete slabs. This applies to all garden rooms self build projects.

Is this one of the best garden room kits uk?

Yes, this garden room kit is a top choice among garden building kits uk. It comes as a flat pack garden room insulated with full instructions. Ideal for self assembly garden rooms uk.

What maintenance does this insulated garden room need?

This insulated garden building is untreated. To keep the 10 year guarantee, treat it annually with wood preservative. This applies to all insulated garden rooms with installation or self build versions.

View full details

Build an additional living space with our 4 x 3m Self-Build Insulated Garden Room.

Looking for extra space at home, need a cost effective solution? A Mercia Insulated Garden Room from allows every possibility. The modular design means you can place the doors and windows in a configuration to suit your needs.

With 72mm thick double skinned walls, double glazed windows and fully insulated roof, floor and walls, this is the perfect space for all-year-round use.

The flat roof creates a contemporary silhouette in your garden, whilst promoting excellent rain water run-off, helping keep your building dry for many years to come. The roof is covered with high-grade mineral felt.

Mercia Insulated Garden Rooms are manufactured here in the UK, using sustainably sourced and regulated timber. The building comes with comprehensive instructions and a step-by-step video guide taking you through every part of the build. All fixtures and fittings are included as standard. We recommend a good understanding of DIY for the construction of this building.

Please Note: A firm and level base is required for this building, either made of solid concrete or concrete slabs. It is recommended that the floor of this garden room is further covered by either carpet or laminate to reduce wear on the matchboards.

Please Note: These Insulated Garden Rooms are NOT pre-treated or painted. In order to qualify for our 10 year anti-rot guarantee the building must be annually treated with a high quality spirit based wood preservative and a waterproof treatment.

Please Note: A firm and level base is required for this building, either made of solid concrete or concrete slabs. It is recommended that the floor of this garden room is further covered by either carpet or laminate to reduce wear on the matchboards.

Please Note: These Insulated Garden Rooms are NOT pre-treated or painted. In order to qualify for our 10 year anti-rot guarantee the building must be annually treated with a high quality spirit based wood preservative and a waterproof treatment.

Specifications

Imperial Size: 14 x 11
Treatment Type: Untreated
Guarantee: 10 Year Guarantee
Cladding: Shiplap+
Roof Material: Tongue and groove
Floor Material: Tongue and groove
Roof Type: Pent
Door Style: Double Door
Building Type: Garden Room
Metric Size: 4 x 3
Under 25: Yes

Dimensions

Width: 13' 8" / 4.17m
Depth: 10' 11" / 3.34m
Eaves Height: 7' 2" / 2.2m
Ridge Height: 7' 8" / 2.36m
Door Width: 4' 11" / 1.51m
Door Height: 6' 0" / 1.85m
Internal Width: 13' 1" / 4.0m
Internal Depth: 9' 10" / 3.0m
Floor Width: 13' 6" / 4.14m
Floor Depth: 10' 3" / 3.14m

Installation Service

Sit back and let us do the hard work! Our installation service is designed to not only save you valuable time but also take the work of moving and constructing the building off your shoulders. Our fully trained, expert fitters work professionally and carefully to ensure that your new garden building is constructed safely and to the highest industry standards.

And don't worry, we make sure to clean up afterwards, taking away excess packaging and leaving you to enjoy your new building.

Learn more at: https://www.gardenarch.co.uk/pages/installation-service

Home Delivery

We offer a fast, free and reliable home delivery service with every order to most UK postcodes. With the ability to pick-a-day that suits you and your schedule, there's no need wait around for days on end.

Our friendly and punctual delivery drivers will deliver your building within 7 - 10 working days of purchase at the front of your property. All of our products are delivered flat packed, to ensure it is easy for you to move the product from the delivery location to the build site.

On the day of delivery you'll be given a two hour delivery slot and our driver will keep in contact with you, so you can make the most of your day.

Learn more at: https://www.gardenarch.co.uk/pages/delivery

Why Choose GardenArch?

See how we compare to other garden arch providers

Features	GardenArch BEST CHOICE	Other Brands	DIY Options
Pricing	✓ Fair, transparent pricing	✗ High costs + hidden fees	✗ Hidden expenses
Shipping	✓ Free	✗ Paid (£100+)	✗ Self-arranged (time + fuel)
Installation	✓ Free professional service	✗ Paid (£500+)	✗ Skill/time required
Material Quality	✓ Premium, durable	✗ Cheap, prone to rot	✓/✗ Depends on builder
Origin	✓ Made in UK (high standards)	✗ Imported (China)	✗ Unverified sources
Anti-Rot Guarantee	✓ 10-year warranty	✗ 1-5 years (weak)	✗ No guarantee
Convenience	✓ All-inclusive, hassle-free	✗ Extra fees + delays	✗ Unpredictable results

GardenArch
BEST CHOICE

Pricing

✓ Fair, transparent pricing

Shipping

✓ Free

Installation

✓ Free professional service

Material Quality

✓ Premium, durable

Origin

✓ Made in UK (high standards)

Anti-Rot Guarantee

✓ 10-year warranty

Convenience

✓ All-inclusive, hassle-free

Other Brands

Pricing

✗ High costs + hidden fees

Shipping

✗ Paid (£100+)

Installation

✗ Paid (£500+)

Material Quality

✗ Cheap, prone to rot

Origin

✗ Imported (China)

Anti-Rot Guarantee

✗ 1-5 years (weak)

Convenience

✗ Extra fees + delays

DIY Options

Pricing

✗ Hidden expenses

Shipping

✗ Self-arranged (time + fuel)

Installation

✗ Skill/time required

Material Quality

✓/✗ Depends on builder

Origin

✗ Unverified sources

Anti-Rot Guarantee

✗ No guarantee

Convenience

✗ Unpredictable results

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The Installation Service Process

Why Choose Us?

Free Pick A Day Delivery
Free Installation Service
100% Made in UK
10 year Anti-Rot Guarantee
100% Satisfaction Guaranteed

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4M X 3M(D) Self Build Insulated Garden Room