Recommendations for Insulation and Best Practices for a Garden Office Conversion

[Mad Professor]

Good day all,

I am seeking advice and recommendations on the best type of insulation and best practices for converting a summerhouse (essentially a glorified shed) into a functional and comfortable garden office.

The space will likely see year-round use, so maintaining a stable and comfortable temperature is my primary concern.

From my research, I understand that converting a shed into a garden office can be a divisive topic in some circles, often leading to heated debates. To be absolutely clear, I am not looking to ignite a flame war or delve into the pros and cons of starting with a shed as the base structure. I’m fully aware that it’s not an ideal starting point, but it’s the one I have, and I’d like to make the most of it.

Additional Details About the Structure:​

• Size: 10x10 ft (3x3 m approximately).
• Roof Beams: 5 inches (127 mm).
• Side Walls: 2.5 inches (63.5 mm).

I am also unsure whether a warm roof or cold roof design would be better suited for this project. I’d appreciate any insights on the pros and cons of each approach, particularly for this type of structure.

Insulation Options I've Considered:​

1. PIR Rigid Foam Insulation
   • Known for its excellent thermal properties and space efficiency. However, I’m curious about how to handle gaps and ensure airtightness effectively.
2. Rockwool Insulation
   • Appealing for its soundproofing and fire-resistant properties, though I understand it might require a vapour barrier to prevent moisture issues.
3. Fibreglass Insulation
   • A cost-effective option, but I’m concerned about its thermal performance and whether it’s the best fit for a structure like mine.
4. Spray Foam Insulation
   • Seems like a versatile solution with great thermal performance, but I’ve heard mixed reviews about breathability and potential long-term issues with timber frames.

Key Considerations:​

• What is the most effective approach to insulating walls, floors, and ceilings, especially given the limited space in the walls?
• Should I prioritise a specific type of vapour barrier or breathable membrane to manage condensation?
• Are there any particular materials or techniques you’d recommend to maximise thermal efficiency and minimise heat loss?

I’m aiming for a practical, cost-effective solution that will provide comfort and longevity. If anyone has undertaken a similar project or has professional insights, I would greatly appreciate your guidance.

Thank you in advance for your time and advice!

 

[Wayners]

I'd use kingspan type as solid.
Mice and rats love rockwool insulation.
I made a office which was used for about 7 years. Gone now as we built extension.

That was a cold roof and we used 25mm kingspan.
I used rock wool in walls and the mice loved it. I use kingspan if I built another

 

[23vc]

Don’t start with a shed as a base structure.

 

[Ivor Windybottom]

Most sheds are too low, or damp, or too flimsy to be of much use.

But photos and measurements would be a good start.

 

[Mad Professor]

Wayners: Thank you for your reply, I must admit I had not even considered rodents in my research and decision making for the conversion.

The Shed / Summerhouse is a Major Pent Modern by Albany Shed Company Limited.
https://www.albanysheds.co.uk/product/3-0x3-0-major-pent-modern/

 

[^woody^]

You won't get payback from more expensive insulation, nor will it necessarily be better as the big problem is air leakage.

Basic quilt will deal with comfort and even temperature, and may be better than rigid board for minimising solar gain. Rockwool for best sound insulation.

You don't need a vapour barrier for a timber building