Energy renovations


Europe requires from all member states to stimulate nearly zero-energy (NZE) building. By 2021, all new buildings and extensive renovations have to be NZE. For public buildings, these requirements apply from 2019. 2/3 of Belgian´s architectural heritage dates from before 1970 and has hardly any energy performance. Consequently, a huge effort needs to be made to renovate all these buildings, in line with NZE, by 2021.

The Flemish Government encourages the construction industry to annually tighten the legislation in the field of thermal insulation, airtight construction and energy technologies. The impact on the build, building design and study process particularly is major.

Bureau Bouwtechniek is on the list of
Because of our large experience with 
NZE-trendsetters and, therefore, is an 
active promotor of the NZE principles. 
renovation projects and projects with extensive
energy ambitions, we have built up a very broad
knowledge over the years which we regularly use for energy renovation projects.


The main objective of an energy renovation is to reduce the energy consumption and increase comfort through the sustainable renovation of a building. It is always a balancing act between energy efficiency, cost-effectiveness, comfort, building management and sustainable materials. We believe this goal can only be achieved by means of interdisciplinary collaboration between the various interested parties. Successful energy renovations require an integrated approach which reflects the whole vision.

At BB, energetic renovation projects are carried out by a multidisciplinary team of building specialists, technical draftsmen, technical energy and installation specialists, led by a project architect. A unique in-house combination of readily available experts. Depending on the specific questions and tasks, we also include external professionals in our team, like a designing architect, a stability engineer or a restoration architect with whom we have already cooperated successfully in the past.


Preliminary study
An in-depth analysis of the current situation is the basis of any renovation plan. Our experts can thereby call on highly sophisticated tools and techniques to get the most accurate and complete picture of the structural condition and current energy performance of the building in question.

The existing technical installation is analysed and the quality of the building envelope is mapped by including in situ research, soundings, air tightness and moisture measurement, thermographic examination, laboratory research on frost resistance of construction materials, etc. The comfort aspect is evaluated by means of logging the air temperature data and the determination of the perceived temperature. The air quality is evaluated by long-term measurements of CO2 and relative humidity.
Heating and cooling needs can be mapped out by taking into account the use of the building.

In consultation with the client, we work out one or more renovation scenarios. For each scenario, the procedures are visualised, the effect on the energy needs and the assessed comfort are evaluated, and the construction costs and payback periods are calculated.

In consultation with the client, a choice between the scenarios is made, after which it is developed further by the team. Once the overall renovation concept and the associated performance requirements are determined, it will be continually adjusted to suit the needs and budget of the client. This requires an interactive process in which all the operations are critically evaluated, and adjusted, if necessary, in order to achieve the completed concept.

Building permit application
Bureau Bouwtechniek makes the building permit application in case planning permission is required for the renovation work.

BB draws up the specifications and supervises the comparison of the contractors´ bids.

During the implementation, BB checks if the work is done in accordance with the technical provisions and predetermined quality in the specifications.

Work management:

  • management of the site meeting with contractors (technical, cost-related, organisational, etc.) 
  • monitoring the quality of the executed work 
  • verification of the contractor's invoices

assistance with the provisional acceptance
assistance with the final acceptance

During the implementation the BB-expert will ensure the objectives in terms of energy consumption are achieved, by using, for example an interim blower-door test.

After commissioning the building, BB monitors the energy consumption and advises the consumer on adjustments for the technical installations.