Civil engineer Lars Ørtoft founded Lars Ørtoft Rådgivende Ingeniørfirma in 2003 after working as an engineer since 1985 primarily as a consulting engineer within energy, indoor climate and HVAC.

In the beginning the company was privately owned, but in 2006 Lars Ørtoft decided to change the company to a joint stock company Ørtoft A/S, consulting engineering firm due to increasing activities.


In 2007, Lars Ørtoft A/S, Rådgivende Ingeniørfirma was admitted to FRI (the Danish Association of Consulting Engineers) www.FRInet.dk .


Ørtoft A/S has provided staff who taught at DTU (Technical University of Denmark) and staff who functioned as judges and assessment experts for the "Arbitration Board".


The company is located at DTU Science Park, Diplomvej 377, 2800 Lyngby, close to the Technical University of Denmark. This gives it a central position in relation to the leading Danish educational institutions and research areas in the field.


The company has taken out 2 low-energy patents and won first prize in the Grundfos Commercial Building Services (Grundfos CBS) international innovation competition and received Gentofte Municipality's environmental award 2009.




The company has approx. 40 years of experience in designing installations for ventilation, heating, water, drainage, indoor climate and energy design.


The company has over 25 years of experience in client consultancy, where the company's planning experience is included to ensure the client the best possible construction that matches the customer's expectations.




Advice for building owners and tenants:

As a building owner or tenant, Ørtoft A/S takes your interests into account so that it is ensured that the future quality meets the customer's wishes.

With Ørtoft A/S as developer, tenant or operational consultant, we look after your interests from idea to finished construction.


Project planning:

Energy, sustainability, water and drainage, ventilation, heating system, indoor climate and daylight simulation and 3D models are just some of the services we offer within construction project design. We also have experience with thermoactive constructions to air-condition buildings in an energy-efficient way, as well as experience in carrying out large energy savings when renovating buildings. Our competences have a broad spectrum. In the areas where we are not the market leader, we request support so that our customers always get the optimal product from a one stop supplier.


For construction and electricity, we typically use sub-consultant from our network of partners.


Expert or second opinion and experience from the Arbitration Board:

Disagreements may arise as to who is responsible for errors under project or construction phase. The resolution of such disputes often requires the involvement of an independent expert, either through a voluntary expert opinion or the civil court. At Ørtoft A/S, we have extensive experience with expert opinions, and our experts always give a professional assessment based on our experience from the Arbitration Board.



Energy screenings:


Our energy optimization starts with carrying out a full screening, where we identify potential energy savings. We can then explain the identified potential, make a profitability calculation and find optimal solutions for the economy as a whole.


Energy concepts:

At Ørtoft A/S, we create energy concepts that take the entire building into account. Based on our many years of experience in low energy and with the creation of energy concepts, we optimize low energy, sustainability, total economy, comfort and room climate for holistic solutions. The company's experience with new patents and innovative solutions is part of our competences.


Low-energy and passive houses:

Ørtoft A/S is a pioneer in low-energy and passive houses. We have been involved from the start and have been able to gather a lot of experience and competences in relation to low-energy and passive houses experiences and competences which we can now include in all the projects we work with as advisers.


Energy renovation:

At Ørtoft A/S, we can give you an overview of the potential for energy savings in your home or portfolio. We offer the complete service from energy screening, development of an energy concept with proven profitability to carrying out an energy renovation and follow-up on the expected savings. In virtually all cases, we find a solution for a macro-economically profitable and comprehensive refurbishment of properties with the energy label E-G, which can significantly improve your energy label, the indoor climate, the operating costs and the value of the property.



The engineering company Ørtoft A/S, www.oertoft.com owns the trademark with name and logo Zero House registered 2nd time 29.11.2021 No 018431108.

The Zero House heat label can be used by buildings that meet the following requirements:

  • Produce electricity for own consumption seen throughout the year
  • Produce heat for own consumption seen throughout the year, possibly via heat pump and self-produced power from solar cells or wind turbines
  • Produce own water for own consumption for washing water and toilet flushing seen throughout the year
  • Cleans own waste water itself throughout the year.

In addition, the building's installations, energy design, climate screen, etc. is designed by Ørtoft A/S.

For a relatively small additional cost, the building can be constructed so that it does not burden the environment. Costs for the documentation are estimated to be a fraction of what other widespread certification schemes cost, such as DGNB, BREAM and LEED, as the work is handled exclusively internally in Ørtoft A/S without payment to an external certification body or with unnecessary document handling.