Few architects in the UK can boast that they listen to environmental consultants, designers or the occupants of their existing projects. And those who learn from their mistakes and use the experience gained in subsequent projects should be included in the Red Book.
Architype, a new generation of enthusiastic architects, have built the first schools in the UK to meet the German Passivhaus standard. By their work, they proved that a school can be not only a beautiful building, but also a building where it is comfortable to study due to its thoughtfulness and energy efficiency.
“Energy is a bit like waste: it's always good if it can be recycled, but it's better to just produce less. Also with energy: you can use its renewable sources, solar panels, or you can just consume less of it."
Jonathan Hines, Director of the Architype Bureau
What is Passivhaus Standard?
As a reminder, this German standard for energy efficiency in buildings, developed by Passivhaus Institut, is an indicator of low energy consumption, comfort in the interior space and the architectural quality of an object. Many people completely in vain believe that it is applicable only to housing: translated from the German “Haus” means not only a house, but any structure, and the standard is suitable for a building of any typology. Its progressiveness is evidenced by the numbers: the standard energy consumption of an ordinary school in England is 100 kWh / m2 per year, and a building built according to the Passivhaus standard should consume no more than 15 kWh / m2 per year. Unlike other standards, Passivhaus helps to reduce energy consumption by optimizing design decisions - such as finding the most compact form, the best building orientation, etc.
The Passivhaus standard is rarely seen in England as local energy efficiency codes work in a completely opposite way. Compared to Passivhaus, the popular green BREEAM standard in England and lobbied by the government has numerous assessment criteria that often have nothing to do with energy consumption: for example, points can be obtained if the distance between the projected building and the nearest mailbox is less than 500 meters. In addition, BREEAM is focused not on reducing the amount of consumed, but on the production of additional energy from renewable sources.
How does a Passivhaus architect work?
First, it minimizes the thermal conductivity of walls, roofs, ceilings and doors. Secondly, he takes care of the thermal tightness of the building: all "cold bridges" (areas of heat loss, most often found at the joints of structural elements of a building) must be reduced to zero or minimized. In addition, already at the initial design stage, the building is modeled using the PHDP (Passive House Design Package) software. However, British architects usually first completely outline the building, think over the layouts and only then give it to the engineers for calculating the energy consumption. They are trying to optimize something, but the probability of correcting errors in the finished project is extremely small. Therefore, it is much more effective to think about this at earlier stages of work, when the project can be significantly changed if required, for example, to keep warm.
The most difficult thing in the Passivhaus standard is checking the object for compliance, where the indicators are not only the calculated data of design engineers, but also real measurements in an already built and operating house. And to build exactly as it was designed is a famous headache for all architects.
Who are Architype Architects?
Architype is a brand new architectural workshop that was founded 29 years ago and has earned an enviable reputation over the years as a designer of quality energy efficient buildings. Their original approach is dictated by the desire to involve customers and future residents in the design process. By experience, they have developed a baggage of technical solutions that increase the quality of the "manufactured product".
During its existence, the Architype team has grown from five to 53 people, despite this they have managed to maintain a fresh creative approach to design, including frequent analysis and discussion of projects. The company's annual turnover is 3 million pounds per year.
Why did Architype decide to apply the Passivhaus standard in England?
About five years ago, Architype, in collaboration with Oxford Brooks University, one of the largest research institutes for energy efficient technologies, collected and analyzed information about the "performance" of school buildings built by the office. As a result, it was found that, despite various energy efficiency strategies, these schools consumed an enormous amount of energy as windows were opened in them during the winter. And at that moment, the adaptation of the Passivhaus standard to the British realities interested Architype, because, thanks to mechanical ventilation and thermal tightness, buildings built according to this standard consumed significantly less energy and generated less CO2. An additional plus was the real opportunity to study how the building “works” and what particular design solutions help to improve energy efficiency the most.
Many architects fear that the Passivhaus standard will limit their imagination. But the architects of Architype argue that it is the rigid framework that they set that triggers a full-fledged creative process in their heads.
Through the use of Passivhaus Architype methods in their recent projects, they have achieved a radical simplification of shapes and details, optimized the design process and even architectural supervision. They manage to achieve the desired results by thinking over each solution step by step and testing its performance in practice. According to bureau director Jonathan Hines, the most important lesson for Architype was the realization of the importance of simplifying the project in general and the structural details in particular.
Since the typology of the building was not a decisive factor, Architype were ready to test the Passivhaus standard on any project. Now, having gained experience in this area, they are designing a university, an archive building, a village with 150 houses, a church and several private houses according to the principles of this standard. However, five years ago, their specialization was school buildings, which is why they became their first Passivhaus proving ground. The only significant requirement of the client of the five schools, Wolverhampton County Council, was to keep within a very modest budget.
To date, Architype has fully completed the construction of two educational institutions - Oakmeadow Elementary School and Bushbury Hill School, and in November 2013 the third - Swillington Elementary School is being completed. All of them replaced obsolete and therefore demolished school buildings, and they owe their appearance to the current government initiative. However, Jonathan Hines believes that the further proliferation of "passive" schools in England is a big question, precisely because of the difficulties with public funding. Therefore, Architype hopes that such projects will be in great demand, for example, in Wales, where the government funding system differs from the English one.
Architectural features of "passive" schools
The design process began with the search for the optimal shape, number of storeys, depth and orientation of the building using the already mentioned dynamic modeling program PHDP. From initial research, it became clear how important a compact building is to reduce energy consumption. Minimizing the building surface area in relation to the floor area made it possible to achieve energy optimization already at the concept stage. For both schools already built, a composition of simple rectangular 2-storey volumes with a central space serving as recreation was ultimately chosen.
The building is designed so that sunlight has access to all school premises, so that artificial lighting is used as little as possible. To reduce the possibility of overheating during the summer months, the number of west and east-facing windows has been reduced to zero, since the sun's rays from a low angle are always more difficult to darken, and therefore the windows face north and south.
All rooms have cross ventilation, which is mainly used in summer and off-season. In addition, during the warmer months, as an additional measure, the central recreation turns into a "chimney", where, thanks to the height difference and the effect of gravity, warm air rises and exits through the upper windows. For winter, ventilation with a heat recovery system is provided. Needless to say, compared to schools where windows are opened for ventilation in the cold season, such a system significantly reduces heat loss. It differs from the standard recuperation system in that the fresh air entering the room is heated by the heat from the processed air from the central recreation. In this space, the air is passively heated by solar radiation and internal heat release, including from schoolchildren running during recess.
Much attention in the project of "passive" schools is paid to the issues of thermal tightness of the building and minimization of the already mentioned "cold bridges" - a problem that is often forgotten in England. Most of these "bridges" are formed in the area of the foundation, since it is in direct contact with the ground, and at the joints of structural elements. The architects found an original answer to this question, proposing to the designers to design a foundation that would be completely insulated and would not touch the ground directly. Initially, the British designers - partners of Architype declared that it was impossible from a technical point of view, despite the fact that in Germany and Austria this method is widely used in the construction of "passive" buildings, but later Architype managed to convince them. In the end, such a solution turned out to be even cheaper than a conventional strip foundation, since the applied method required less excavation. When such a system was implemented, the number of "cold bridges" in the area of the foundation was reduced to zero.
To get rid of "cold bridges" at the joints of structural elements, the architects came up with the idea of dividing the building structure into an internal and an external part. The entire internal part of the structure is completely wrapped in a layer of thermal insulation called "blanket", and therefore is completely sealed. Moreover, the thermal insulation of the foundation adjoins the thermal insulation of the walls, creating a closed loop, which made it possible to completely solve the problem of "cold bridges". However, due to this solution, the canopies, awnings and similar facade elements had to be attached to additional external structures that were not connected to the main frame.
Particular attention was paid to the simplification of structural components. The project team had to spend a lot of effort to find a balance between heat loss through the windows and solar radiation, which is important for passive heating, which ultimately led to strict control over all windows and doors in the building.
All materials used in the construction of schools are environmentally friendly and for the most part were produced in England itself, which minimized CO2 emissions from the transport of materials. We also used Warmcell - thermal insulation made from recycled newsprint.
In the first month and a half after the completion of construction, the architects visited their schools every week (then - once every two weeks and once a month) in order to monitor the functioning of all systems and understand how its inhabitants feel in the building. In addition to measuring the amount of energy consumed, CO2 levels, temperature and humidity, Architype asked all school staff to take notes on how the building “works” and how they feel in it. All this information was collected and discussed in meetings with contractors in order to improve future projects.
Thus, in one of the first school projects, it was discovered that the level of consumed primary energy significantly exceeds the norm. This was caused by the presence of heating in the sprinkler pump room, which was not thermally insulated. On the other hand, in the course of monitoring, the architects found that the heat recovery ventilation system makes children more attentive in the classroom, as they breathe fresh air.
Since the building is perfectly insulated and hermetically sealed, one domestic boiler is enough to heat it, as apartments are usually heated in England, but during the design, the school technical service asked to install a second, additional boiler - which later, of course, turned out to be superfluous. The commission that inspected the building drew attention to the fact that, despite the cold weather, both boilers were turned off - since even without heating the inside of the building remained at a comfortable temperature.
Throughout the monitoring period, which lasted a year, the architects told the staff of their schools how to correctly use lighting, ventilation and other systems in such an unusual building and even published an illustrated "user manual". Architype also spent a lot of time explaining to the students why they need energy, where to get it and, most importantly, how to save it. Also, schoolchildren were allowed to make comments to teachers if they, for example, forgot to turn off the light. Children were delighted with such a prospect, which cannot be said about teachers.
According to the results of the monitoring year, it was found that the “passive” school buildings of Architype actually consume no more than 14-15 kWh / m2 per year, while earlier schools of the same architects consumed 40-50 kWh / m2 per year; however, ordinary schools in England consume 100 kWh / m2 per year.
Analyzing the entire process of creating and implementing a project, we can conclude that success is largely due to the well-coordinated work of the entire team: the customer with whom Architype has been cooperating for many years, the contractor, architects and designers. Numerous meetings and negotiations allowed all team members from the very beginning to clearly understand what is being done and why. A huge number of inspections and tests have also been carried out, including a smoke test, which determines the tightness of the building.
Architype has managed to achieve amazing results using the Passivhaus standard as a design tool and without spending any additional funds on energy efficient technologies (although usually Passivhaus buildings pay off quite quickly: on average 5-10 years depending on energy prices). By basing their workflow on observing what and how “works” in a building, these architects strive for quality by simplifying the building itself and its details, while proving that energy efficiency does not conflict with beauty and elegance. As musician Charles Mingus said, “Complicating simplicity is commonplace. And the simplification of complexity is creativity”: this is the philosophy that the Architype workshop adheres to.
