A fixed price, fully calculated
You get a binding fixed price instead of a rough estimate. Work you have to provide on site is listed separately in the quote, everything else is included.
Energy-efficient renovation in Mannheim: one contact, one fixed price
Heat pump, solar PV, wallbox and more from a single source. Quote within 48 hours of the on-site visit.
- Fixed price instead of a rough estimate
- Quote within 48 hours of the visit
- One contact for every trade
Benefits
Why BEST BAU: fixed price, 48 hours, one contact
BEST BAU GmbH is a general contractor for energy-efficient renovation in Mannheim and the Rhine-Neckar region. We plan, coordinate and hand over turnkey, with qualified specialist companies doing the work. These are the four commitments you can hold us to.
One contact for every trade
From planning through grid operator and funding application to handover, you deal with one person. We coordinate the specialist companies so you do not have to.
Quote within 48 hours
After the on-site visit, your complete fixed-price quote is with you within 48 hours.
A binding schedule
From order confirmation to handover: air conditioning 2 weeks, solar PV and wallbox 4, heat pump 6, windows and doors 8 weeks. For standard systems, secured delivery and funding approval in place.
Heat pumps, solar PV, wallbox and more: our services
We offer every service of energy-efficient renovation from a single source: heating, electricity, charging, cooling, windows and insulation. You get one quote, one schedule and one contact, even when several trades are involved.
Heat pumps in Mannheim
Planned from your heating load and often combined with solar PV. You become independent of fossil fuels, and we support the funding application.
6 weeks from order confirmation to handover
Solar PV with storage
Your own electricity lowers your power bill, and storage makes it usable in the evening too. Planning, installation and grid registration come from one source.
4 weeks from order confirmation to handover
Wallbox systems
For houses, underground car parks and company car parks. We connect large systems in series without upgrading the electrics and prepare them for later expansion.
4 weeks for standard wallboxes
Air conditioning
We determine your cooling demand and plan the right system, so it stays comfortable inside when it is hot outside.
2 weeks to commissioning
Windows and doors
Quality and security windows and doors in any size, with a fast quote and fast delivery.
8 weeks to handover
Construction work
Facade insulation, underfloor heating, tiling: we bundle the trades and coordinate them. Planning, execution and handover come from one source, at the best price-performance ratio on the market.
Energy consulting
With the energy consultants of our partner EnBau Consulting you identify savings, avoid wrong investments and make use of funding.
Fuel cell for homes
A fuel cell produces electricity and heat at the same time, all year round. It runs on natural gas, and a switch to hydrogen is possible. We check funding options beforehand.
Fuel cell for businesses and biogas plants
For businesses with high electricity and heat demand all year round. For biogas plants whose funding is expiring, we assess follow-on use.
Your project is not listed?
Tell us what you have in mind. We will tell you honestly whether and how we can do it.
Request a free quoteTimes apply from order confirmation for standard systems, secured delivery and, where needed, funding approval in place.
Solutions for owners, property managers, businesses and insurance claims
Whether a family home, an owners’ association or a business: we shape the offer and process around whoever decides on your side.
For owners of residential property
You want to cut energy costs and raise the value of your property. We plan the measures in the right order, support funding and grid registration, and coordinate all trades.
- Heat pump, solar PV and insulation matched to each other
- Fixed price and fixed schedule instead of open items
- We support the funding application and grid registration
For property managers and owners’ associations
You need solid documents for the owners’ meeting. We deliver decision-ready comparison quotes within a week when a reference quote is available, and handle execution and annual maintenance.
- EV charging infrastructure for car parks with load management
- Reply within 48 hours
- Annual maintenance of building services
For businesses and commercial property
You want to cut operating costs and enhance your property in the long term. We plan solar PV, charging points, heating and fuel cells for your site.
- Solar PV for the company roof
- Charging points for staff and fleet
- Fuel cell for high year-round demand
For insurance claims
After damage, those affected, property managers, brokers and assessors need a company that coordinates instead of putting them off. We handle the restoration and arrange qualified specialist companies.
- Restoration handled from one source
- Qualified specialist companies for every trade
- One contact for everyone involved
How your project runs: from the first conversation to handover
Five steps, so it is clear beforehand what happens when and who your contact is.
Enquiry
You write or call. We arrange an appointment at your property.
On-site visit
We survey your property and clarify needs, space and funding options.
Fixed-price quote
Within 48 hours you receive a complete quote. Work to be provided on site is listed separately, everything else is included in the fixed price.
Execution
Qualified specialist companies carry out the work. We coordinate dates, delivery and grid operator, and you have one contact.
Handover and service
We hand over the system together with you and remain your contact afterwards, including for annual maintenance.
“The rising energy costs are a wake-up call for all of us. We must focus on renewable energy to reduce costs and climate change in the long term.”
Make your home fit for the future today.
Request a free quoteWho is behind BEST BAU
BEST BAU was founded as an alliance of several specialist fields to offer the full range of services around the house, with a clear focus on energy technology. Our aim: the best overall package on the market.
We are your contractual partner and general contractor. We plan, coordinate and hand over turnkey, while qualified, registered specialist companies carry out the trade work. As your contractual partner we stand behind the overall result, and you have one contact instead of several.
- Over 26 years of trade experience come from one of our founders.
- Service area: Mannheim and the Rhine-Neckar region
- Manufacturer-independent: we choose the technology to fit your needs
Marko Cacic
Founder and managing director
Felix Wenz
Founder and managing director
A network for everything around the house
With reliable partners we cover topics beyond construction: energy consulting, expert reports, planning, insurance, financing, real estate, fire protection and pools. For the technology we stay manufacturer-independent and choose the right solution with you.
Energy consulting
EnBau Consulting. Energy consulting, building surveys, structural engineering and technical questions on energy systems.
PV expert
Dr. Tobias Vögele. PV expert reports, PV project consulting and construction management for large installations.
Architecture
Tolga Akcay, Freier Architekt. Architectural services, practical living concepts and preliminary planning.
Insurance
AMEO Gruppe. Independent agency that puts together the right insurance package for you.
Financing
Heun Finanz. Family-run financing advisers with access to over 400 banks, at your side throughout the loan term.
Real estate
ImForum Immobilien. Buying, selling, valuation and letting of properties.
Fire protection
a|sh Brandschutz. Certified fire protection experts, from planning to commissioning.
Pools and wellness
Rhein-Neckar Pools. Planning and construction of your pool.
Frequently asked questions
Short answers to what owners, property managers and businesses want to know before placing an order.
What is included in the fixed price?
Everything needed for a ready-to-use handover. Work that has to be provided on site is always listed separately in the quote. Everything else is included in the fixed price.
Who carries out the work?
Qualified, registered specialist companies from the region. BEST BAU is your contractual partner: we plan, coordinate and hand over the result. You have one fixed contact and do not have to deal with individual trades.
How fast do I get a quote, and when is everything finished?
After the on-site visit you receive a complete fixed-price quote within 48 hours. From order confirmation to handover we plan for standard systems: air conditioning 2 weeks, solar PV and wallbox 4, heat pump 6, windows and doors 8 weeks, each with secured delivery and funding approval in place.
What funding is available for a heat pump?
According to the KfW fact sheet on heating funding (as of September 2026), there is a basic grant of 30 percent. Owner-occupiers replacing an old oil or gas heating system receive a further 16 percent if they apply by 31 January 2027, plus an income-related bonus. In total, up to 70 percent of eligible costs of at most 28,000 euros are possible. All details without guarantee; we check your options at the on-site visit.
Do I have to replace my heating because of the new law?
No. Since 29 July 2026 the Building Modernisation Act applies, and the former 65 percent requirement has been dropped. New fossil heating systems do become more expensive to run through rising shares of biofuels and the CO2 price. We calculate both routes for you.
Is solar PV worthwhile without a high feed-in tariff?
Yes, if you use the electricity yourself. Self-generated electricity costs between 6.3 and 14.4 cents per kilowatt hour according to Fraunhofer ISE, while grid electricity currently costs around 37 cents (BDEW, August 2026). The fixed tariff for new small systems is planned to end from 2027, but the law has not yet been passed (as of October 2026). Storage increases self-consumption.
How does payment work?
Payment is made in instalments. Instalments and due dates are stated in advance in your quote and in our general terms and conditions. A fixed price stays a fixed price.
Do you also work for property managers and businesses, and in which area?
Yes. We work in Mannheim and the Rhine-Neckar region for owners, property managers, owners’ associations and businesses. For property managers we prepare decision-ready comparison quotes, for businesses we plan solar PV, charging points and heating.
Contact
Request a free quote
Tell us briefly what it is about. We will get in touch to arrange an on-site appointment. The quote is free and non-binding.
- BEST BAU GmbH
U4, 8
68161 Mannheim - +49 621 18062340
- info@bestbau24.de
- Monday to Saturday
8 am to 6 pm
Urgent? Give us a call, we are available Monday to Saturday from 8 am to 6 pm.
How to find us
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