Joe Claydon & Sons Ltd - Hertford

AKN Engineering Limited - Bishop's Stortford

AD Bly Construction - Welwyn

Baobab Engineering Ltd -

Howe Engineering - Buntingford

Gtek Plant Limited - Buntingford

All Terrain Engineering - Buntingford

Newgate Civil Engineering - Royston

North Yorkshire Project Management Ltd - Middlesbrough

Edinburgh Project Management Ltd - Peebles