Introduction to Optibuild

Optibuild is a computer program designed to determine the most economical combination of energy saving measures for any given building. The optimisation is based on achieving the lowest life cycle cost of the building by trying every possible combination of known energy saving measures.

The space heating calculations are based on the CEN-standard PREN 832. The energy consumption for domestic hot water and electricity are also calculated. The cold water consump­tion is also considered in order to present the total expenditure of the building.

The energy saving measures are collected in a large database that contains detailed information concerning both energy and economy. The database is the main element in the optimisation routine.

To illustrate the importance of the Optibuild database, please consider the windows in a rehabilitation project. Is it profitable to change the one layer windows to two layer windows or maybe to super low-energy windows? The Optibuild database contains information about several windows. Each window is described by: U-value, solar heat gain coeffecient, investment cost, maintenance cost and lifespan. By calculating life cycle cost for each window in the building (and all the other energy saving measures in the database) Optibuild can decide which window is the best. This routine ensures that new technologies can compete with traditional solutions because personal preferences is avoided.

Optibuild considers the following energy saving measures:

·      Standard insulation of walls, roof & floor

·      Solar heating for DHW & space heating

·      Heat recovery of ventilation air

·      Windows

·      PV-modules

·      Water savings

·      Electricity savings

·      Improvement of distribution systems (DHW and space heating)

·      Change in furnace or energy source