Services · From the model to handover
Services for Passive House and nZEB homes
Four services, in the order they come up in a new build or a renovation: the energy model in PHPP, the HVAC design, the site checks and the project management. They are provided by Dezideriu Florian Pana, Certified Passive House Consultant, certified by the Passive House Institute (Darmstadt), with over 40 HVAC projects in Romania and 3 projects in the Netherlands. Take them separately or together; tell us what stage the house is at and we will tell you what makes sense at that point.
- Certification
- Passive House Institute, Darmstadt
- Projects
- Over 40 HVAC in Romania · 3 in the Netherlands
- Area
- Romania and abroad
- Calculation tool
- PHPP (Passive House Planning Package)
Stage 1
Energy design in PHPP
When
At the architectural design stage, before the building permit: that is when insulation, windows, orientation and shading can still change at no cost. For renovations, before the works are decided.
What we do
We model the whole house in PHPP (Passive House Planning Package), the Passive House Institute's calculation tool: losses through the envelope and through ventilation, solar and internal gains, heating and cooling demand, overheating risk and primary energy, month by month. We compare the options in numbers (insulation thickness, window type, shading, ventilation) and check the result against the Passive House criteria (at most 15 kWh/(m²·a) or 10 W/m², n50 at most 0.6 h⁻¹, at most 10 % of hours above 25 °C) or against the Romanian nZEB minimums of Mc 001-2022.
What you get
- The PHPP model of the house and a report with the options compared.
- The recommended U-values for each element: roof, walls, floor, windows.
- The details that decide the result: thermal bridges and the airtightness layer.
- The figures the building services are sized on.
A PHPP model for your house
A complete model is 2–3 full days of work. We set the date at the start, once we have seen the design.
Review of an existing design
If the architectural design is already done, we run it through PHPP and tell you, in numbers, where it loses and what is worth changing before the permit or the building site.
Stage 2
HVAC design
When
After the energy model, or on an existing design that already has a heating-demand calculation.
What we do
Heating, cooling, heat-recovery ventilation and hot water, sized on the house's calculated demand, not on square metres. Ventilation: the air flow for each room (30 m³/h per person, at least 0.30 air changes per hour), the duct routing, the unit requirements to the PHI criteria (heat recovery at least 75 %, at most 0.45 Wh/m³, at most 25 dB(A) in rooms). Heat pump: the capacity, the flow temperature (underfloor heating at 35 °C), domestic hot water, summer operation.
What you get
- The drawings and schematics of the building services.
- The room-by-room flow table.
- The equipment schedule with the required performance, no imposed brands.
- The sizing notes for the installer.
Heat-recovery ventilation design
The flow for each room, air moving from the rooms towards the kitchen and bathrooms, the unit chosen to the PHI criteria. You can see the figures for your house in the ventilation calculator. Heat recovery ventilation calculator →
Heat pump sizing
The capacity follows the house's calculated demand, not its floor area; an oversized heat pump starts and stops often and costs more. The heat pump calculator shows the order of magnitude for your city. Heat pump calculator: air-to-water, air-to-air, ground source →
Stage 3
Site checks
When
At the stages that can still be corrected, before they are covered: the insulation under the slab and at the plinth, the window installation, the airtightness layer before finishes, the continuity of the insulation, the ductwork, the commissioning of the building services.
What we do
We come to the site at these moments and check the work against the design: the sealing, the window installation, the insulation, the ductwork. The airtightness test (blower door) before finishes.
What you get
- After each visit, a short report with photographs.
- What is right and what has to be redone before work continues.
Checking the airtightness and the window installation
Window reveals, service penetrations and the wall-to-roof junction are where airtightness is lost; we check them while they are still visible. Thermal bridges and mould →
Stage 4
Project management
When
From concept to handover.
What we do
We coordinate the teams (architect, engineers, builder, installers), the schedule and the technical decisions that affect energy use. Site meetings at fixed intervals and a monthly report. Does not include the statutory site supervision ("dirigenție de șantier") under Romanian Law 10/1995.
What you get
- A single point of contact for the whole project.
- The decision log.
- The periodic reports.
Example
A project done this way
The 1965 house in Limburg (Netherlands), about 160 m²: from energy label F and about 3,000 m³ of gas a year to a heating demand of about 10 kWh/(m²·a) in PHPP; it now produces more energy than it uses. All four services, from the model to handover.
Contact
How we start
Email or call. Tell us what stage the house is at: an idea, a design in progress or a building site. We reply with the services that fit that stage and a realistic date.
Common questions about the services
Can I take only the HVAC design, without the PHPP model?
Yes, if the design already has a heating-demand calculation we can rely on. If not, we build the model first: building services are sized on figures, not on estimates.
Do you work with my architect?
Yes. The PHPP model is most useful when it is done together with the architect, before the permit.
Do you also do renovations?
Yes. The Limburg house is a deep renovation; Romanian houses from the 1960s–1980s have the same problems: uninsulated walls, thermal bridges, poor windows.
What stage is your house at?
Write us two lines about the house and the stage. We will tell you which service makes sense now and which calculations are worth doing.
Published 9 November 2026.