# TRJ Construction Ltd

> TRJ Construction Ltd designs and builds bespoke Structural Insulated Panel (SIP) granny annexes, garden rooms and other garden buildings. Costi Tiseanu leads the company. The website presents services, building methods, project photographs and customer reviews, with work across Hertfordshire, North London and surrounding areas.

SIPs have structural faces bonded to an insulated core. Building specifications, prices and timescales depend on the agreed design, site conditions, access, services and fit-out. The calculator gives an estimate; the project quotation confirms the scope and price. Planning and Building Control requirements must be checked for the individual site.

## Company and contact

- [About Costi and TRJ](https://trj-construction.co.uk/about-us/): Construction experience, approach and service areas.
- [Contact TRJ](https://trj-construction.co.uk/contact/): Discuss a project and request a quotation.
- [Customer reviews](https://trj-construction.co.uk/testimonials/): Customer accounts and photographs of their projects.

## Buildings and services

- [Granny annexes](https://trj-construction.co.uk/granny-annexes/): Bespoke self-contained garden accommodation.
- [Garden rooms](https://trj-construction.co.uk/garden-rooms/): Spaces for work, hobbies, exercise and other uses.
- [Services](https://trj-construction.co.uk/services/): TRJ's building services and links to relevant project examples.
- [Commercial SIP buildings](https://trj-construction.co.uk/commercial-buildings/): Includes the 2017 Royal College of Art annexe in Battersea.
- [The Rowan](https://trj-construction.co.uk/the-rowan/): Annexe layout and specification.
- [The Ash](https://trj-construction.co.uk/the-ash/): Annexe layout and specification.
- [The Oak Accessible](https://trj-construction.co.uk/the-oak-accessible/): Annexe layout and specification.

## Design, construction and cost

- [Build process](https://trj-construction.co.uk/how-its-made/): How TRJ plans and constructs a building.
- [What's included](https://trj-construction.co.uk/included/): Standard scope and specification information; individual quotations take precedence.
- [SIP panels](https://trj-construction.co.uk/sip-panels/): Explanation of Structural Insulated Panels.
- [Planning permission](https://trj-construction.co.uk/planning-permission/): Project planning support and considerations.
- [Cost guide and calculator](https://trj-construction.co.uk/granny-annexe-prices-calculator/): Indicative costs and factors that affect a quotation.
- [Frequently asked questions](https://trj-construction.co.uk/faq/): Answers to common project questions.

## Project evidence

- [Completed projects](https://trj-construction.co.uk/completed-projects/): Project portfolio and photographs.
- [Waltham Cross annexe](https://trj-construction.co.uk/granny-annexe-waltham-cross-hertfordshire/): An approximately 8m by 5m garden annexe with a kitchenette, separate room and shower room.
- [Borehamwood garden room](https://trj-construction.co.uk/bespoke-sip-garden-room-with-hidden-storage-in-borehamwood/): A garden room with storage.
- [Chiswell Green garden room](https://trj-construction.co.uk/large-sip-garden-room-with-storage-in-chiswell-green/): A SIP garden room with storage.

## Optional

- [TRJ blog](https://trj-construction.co.uk/blog/): Articles about garden buildings and SIP construction; check publication dates for time-sensitive information.
- [Website sitemap](https://trj-construction.co.uk/sitemap_index.xml): Index of public website pages.