Warsaw 27 February 2014
Defective skylights currently cost Polish retail industry millions of Euros a year in energy loss. So far the extra over cost is picked up by the retail centre tenants who share in the loss. Since 2013 SOLIDEA Group EVE® team have surveyed over 1 million m2 of Retail Roofing in Poland reporting that more than 80% of skylight smoke vents are found to be defective the majority only needing simple adjustment.
In 2013 The Skylights Were The Highlights
Comparing surveyed retail centres in Poland the Czech and Slovak republics in 2013 Poland has without question issues with skylights. Smoke ventilation skylights are installed according to the local fire requirements in the European Union, it usually means that between 3% and 5% of the total roof area is operable to evacuate smoke in the event of a fire. On large retail projects as much as 20% “EV” [Energy Variation] occurs as a result of defective smoke vents. “EV” is a negative it means energy loss.
Generally there are two types of smoke vents, these are one proprietary smoke ventilation units and two operable window systems often built into inclined glazed curtain walling which make up skylights over atrium etc. Proprietary smoke ventilation units generally make up the majority of the smoke evacuation systems. Large projects can deploy even several hundred vents on any one roof.
“During 2013 EVE® team reported the biggest recurring single defect in retail building conditional surveys in Poland are attributed to proprietary smoke vent skylights. It is the single greatest source of energy loss or origination in defect in the retail centre envelope despite being one of the most easiest to avoid or fix”
More than 80% of those proprietary smoke ventilation hatches EVE® team had surveyed were defective as a result of not being installed tight in the first place and usually because of manufacturers defect not installers defect. It is a common misconception of the industry that energy loss in mechanically controlled building occurs as a result of lack of air-tightness and not through defective or lack of insulation.
Most of the proprietary smoke hatches EVE® team survey are defective through lack of air-tightness and whilst more than 80% failed the air tightness test surprisingly less than 20% of the skylights inspected were defective as a result of cold bridging or defective insulation.
EVE® team has Zero Tolerance Of Supplier Disputes
During the last 12 month the EVE® team has been in direct or indirect dispute with 3 of the top 5 suppliers of proprietary smoke hatches in Poland and without mercy. A common misconception of suppliers and buyers is that air-tightness and insulation are one and the same thing. The Polish code does not require well insulated skylight ventilation but it does require smoke and other ventilation units to be installed tight in order for it to be safe. Suppliers are likely to quote insulation issues in disputes mistaking quoting insulation code requirements when its air-tightness which is defective and costing the industry.
“Proprietary skylights for smoke evacuation are relatively low cost however, low cost and installed defective they can demonstrate their value in heat loss several times over even in one year.”
In Poland every skylight manufacturer requires an ITB test and certification before offering proprietary skylights for construction. ITB tests are usually offered in summary of one page it is recommended to however to read all thirty something pages of the test report. One of the key tests in the ITB certification process requires skylight manufacturers to produce tight fittings. It is a fact that lack of tightness can be life threatening if smoke ventilation hatches are not able to perform. During the course of due diligence exercises or overseeing hand over EVE® team has had to insist asset owners request the full ITB certification from the product supplier as the design and build team had failed to collect and complete concise documentation during procurement and building handover.
“In Poland most retail buildings are handed over defective at practical completion, they remain defective during defects liability period until the warranty period ends when defective air-tightness becomes critical and the responsibility of the asset owner. These defect costs asset owners and their tenants dearly it occurs as a direct impact from defective installation of smoke hatches or skylight vents.”
A Common Misconception Ironed Out
During a recent recruitment campaign in Poland EVE® team were quite surprised that many surveyors and architects simply do not know the difference between air-tightness and insulation. Any wonder then and no surprise that many professionals are unable to explain the impact of the two on the enclosed environment and especially how buildings which are handed over by “visual inspection only” can have such a very high level of defect.
Many of our designers and constructors here in Poland believe that a well insulated building will be hyper efficient demonstrating low energy use. Unfortunately the performance of commercial real estate with mechanical systems and background heating in Winter is not so uncomplicated.
Everything was fine so long as the owner was not responsible and the tenant didn’t mind
Without air-tightness buildings which operate with mechanically air handling systems cannot maintain designed building comfort the fact is buildings are designed to be tight. If undue air leakage occurs whole building systems will become defective creating poor building user environments even building sickness. This phenomenon can easily be demonstrated in the family car if the back window is down, the air conditioning does not work properly. Similarly the family car also demonstrates how buildings could be kept cool with less insulation and far better controlled [sound] air tightness.
SOLIDEA Group EVE® team carry FLIR IR cameras as standard practice we are able to deploy Blower Door Tests up to 1 million m2 and our AerialEVE® UAV’s under development will soon provide our larger clients with 3D IR modelling to combat energy loss. EVE® is not a specialist service we provide EVE® for all forms of Technical Condition Due Diligence and to compete with or oversee other RICS qualified firms.