Project sequence in modular construction

Building with ALHO as general contractor

Because the project sequence in modular construction is different from that applied in conventional building methods, owners and developers who would like to carry out their construction project using the modular method of construction will contact a general contractor specialising in modular construction. ALHO thus also works as a general contractor for its clients, as a rule. This means that we provide all the building services involved in construction. We complete the building so that it is ready for use. During the construction period, we may contract out some of the work required to subcontractors

However, this does not alter the fact that ALHO, as the general contractor, is the developer's sole contract partner and bears full responsibility for the overall service. If the customer wishes, we also offer to provide the planning services. If these are then provided in addition, ALHO is acting as the sole contractor. We answer further questions about the project sequence in modular construction in the following.

What are the construction periods like in modular construction?

In modular construction, the buildings are up to 70% prefabricated as ready-to-assemble modules in the factor and then transported to the construction site. As a rule, the modules can be assembly cleanly and quietly in just a few days. After this, the inter-modular connections must be completed and the roof and facade added. The construction time on site – module assembly and finishing work – is shortened to an average of 10 to 14 weeks, which is a major advantage for inner-city construction site and construction alongside existing buildings, since dirt and noise pollution are reduced to a minimum.

How long is the timespan from placing the order to handing over the project?

With the modular grid, planning can be carried out quickly and efficiently. System reports, type-tested static analyses and reliable technical details speed up the approval process and execution planning. Through series manufacture with standardised production sequences, we are able to achieve a high level of prefabrication and to carry on building throughout the year, irrespective of the weather. This high level of prefabrication of the modules, in turn, means that the construction time on site is massively shorter. All in all, the building process is reduced by around 70% in comparison with conventional building methods.

Who is the best person, logically speaking, to take on the design planning of a modular building?

Essentially, it is possible to place any design in a modular grid and thus make it applicable for modular construction. Minor adjustments may be necessary afterwards, however. The design planning can therefore be taken over by an external architect appointed by the owner or developer. The design planning also already often exists before the modular method of construction is considered as an alternative. Then it is a question of finding a grid together which takes aesthetic, financial and technical requirements into account equally.

Ideally, however, the decision to use modular construction methods is made from the very beginning, so that the external architect and modular construction manufacturer can work hand in hand even in the early planning stages. This offers planners the opportunity to learn about what is legally allowed with modular construction and to exploit this knowledge to the full. 

If no design plan exists and the owner or developer has no architect on hand, our in-house architects are happy to take on the design planning or we will recommend a firm of architects specialising in modular construction.

Does ALHO also carry out the approval planning for modular buildings?

We either support the architect employed by the owner or developer in the approval planning process by providing all the documents relating to the system, or we take on the approval planning for our clients. Both options are possible and are regularly practiced by us. Thanks to the system reports, type-tested static analyses and reliable technical details available for modular constructions, the approval process is much simpler and faster.

Where are the modules produced?

The modules are produced in the main ALHO Systembau GmbH factory in Friesenhagen. Depending on capacity utilisation, production may also be outsourced to the ALHO Group's other factories in Dresden, Mitry Mory (France) and  Wikon (Switzerland). In total, the ALHO Group has production facilities cover over 72,000 m2. Each year, around 12,000 modules leave the factories, corresponding to a manufacturing capacity of around 200,000 m2.

Quality management in modular construction – how is it guaranteed?

In the ALHO "room factory", the modules are produced in consistently good conditions, irrespective of the weather. Continuous quality controls are carried out throughout the production process. Qualified, skilled staff and subcontractors who have been trained for years also help to ensure quality. In addition, we only use quality-tested branded products made by German manufacturers. This certified series production in our factories achieves a higher standard of quality than is possible using conventional building methods.

Should I expect restrictions, such as noise problems, on site?

Modular construction is an industrial form of building. A high proportion of the building work is carried out in production sheds, and the modules are up to 90% prefabricated when they leave the factory. This means that only a small proportion of the building work is actually carried out on site. The construction time on site, from module assembly through to the finishing of the interior work and completion of the facade, is only around 10 to 12 weeks. Noise and dirt pollution on the construction site is reduced to a minimum. The modular method of construction is therefore also ideal for construction work in existing contexts, since operations can be continued without any disturbance from building noise or dirt.

In modular construction, which service categories under the HOAI fee regulations can be carried out by an external architect?

In modular construction, an external architect can provide service categories 1 to 4. From Phase 5, execution planning, the modular construction specialist takes over. Many architects value having a modular construction expert, as a strong partner, by their side after the design and approval planning. These experts are able – where necessary – to take over the subsequent, often routine elements during the construction period, such as factory and detail planning, time-consuming calls to tender or "dirty" phases such as on-site support. 

Admittedly, concentrating on service categories 1 to 4 does not necessarily match the well-known traditional performance profile of an architect, but with the modular construction partner as the general contractor, it is possible to take on new commissions sooner and to concentrate more on service categories that are more financially worthwhile – i.e., the design.