This is the chemical formula of Topaz – the hardest of any silicate material and in its natural state is a golden brown to yellow. A variety of impurities and treatments may make Topaz wine red, pale grey, reddish-orange, pale green, or pink (rare), and opaque to translucent/transparent. The pink and red varieties come from chromium replacing aluminium in its crystalline structure.

Topaz Apartments in Hounslow High Street which is the latest property awarded to CEM by Haus Block Management. The property consists of Block A (40 apartments) on the High Street and Block B (21 apartments) immediately behind.

The properties were completed around 4 years ago and served by a single communal plant room.

Haus was established in 2008 and is privately owned, they manage around 150 residential and mixed-use buildings in and around central London. They are based at 266 Kingsland Road, London E8 4DG. Tel: 020 7275 2041 Website:

Contract Energy Management Limited was formed in 1993 and its two founding Directors are still running the company. For all of the company’s existence the core business has been looking after communal plant rooms like the one serving Topaz Apartments.

CEM provide planned preventative maintenance contracts, remedial works and complete plant room refurbishments. On the latter we work closely with a range of M&E consultants and also offer a full Design & Build service. A more recent development has been CEM’s partnership with the global leading manufacturer of plate heat exchangers, Alfa Laval, who appointed CEM an Authorised Service Partner three years ago and more recently a Distributor of their HVAC products.

The Alfa Laval relationship has enabled CEM to develop business with leading players in the district heating scheme arena – e.g. Engie, E.on and Mace. In addition, utilising Alfa Laval solutions to provide extremely efficient and cost-effective hot water solutions to a range of clients. In 2018 to date this includes a major refurbishment of Reddam School in Wokingham, St George’s Hill Golf Club in Weybridge and 22-23 Down Street, Mayfair. Currently work is underway to completely refurbish the plants rooms within three large residential blocks in Eton College Road, NW3.