Romsey Structural Engineering Ltd specialises in home extensions. Designs are by Chartered Structural Engineer Mike Byfield, author of "Structural design from first principles" (available from Amazon). Builders often ask for site visits, which cost £250 from most engineers; Romsey Structural do not charge for additional visits. Choosing the lowest price design can lead to quality and cost problems; equivalent quotes should include steelwork connection design. With Romsey Structural, the agreed fee is a lump sum without add-ons. Check Google reviews and contact Mike by phone or email for a fixed price quote.